{"id":8823,"date":"2015-03-20T12:39:08","date_gmt":"2015-03-20T17:39:08","guid":{"rendered":"https:\/\/www.masterorganicchemistry.com\/?p=8823"},"modified":"2025-05-14T13:05:06","modified_gmt":"2025-05-14T18:05:06","slug":"pbr3-and-socl2","status":"publish","type":"post","link":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/","title":{"rendered":"PBr3 and SOCl2"},"content":{"rendered":"<p><strong>PBr<sub>3<\/sub> and SOCl<sub>2<\/sub>: Reagents For Converting Alcohols To Good Leaving Groups<\/strong><\/p>\n<ul>\n<li>Alcohols can be converted into alkyl halides with phosphorus tribromide (PBr<sub>3<\/sub>) or thionyl chloride (SOCl<sub>2<\/sub>).<\/li>\n<li>The reaction with PBr<sub>3<\/sub> occurs with <strong>inversion<\/strong> of configuration at carbon.<\/li>\n<li>The reaction with SOCl<sub>2<\/sub> also occurs with <strong>inversion<\/strong> of configuration [<span style=\"color: #993366;\"><em>but check with your instructor to see if they cover the <a href=\"https:\/\/www.masterorganicchemistry.com\/2014\/02\/10\/socl2-and-the-sni-mechanism\/\">S<sub>N<\/sub>i mechanism<\/a><\/em><\/span>]<\/li>\n<li>Using PBr<sub>3<\/sub> and SOCl<sub>2<\/sub> is much more <strong>mild<\/strong> and <strong>predictable<\/strong> than using HBr or HCl to convert alcohols to alkyl halides since it avoids the possibility of carbocation rearrangements.<\/li>\n<\/ul>\n<h2><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone wp-image-15205\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif\" alt=\"summary of pbr3 phosphorus tribromide and socl2 thionyl chloride both result in inversion of configuration of alcohol conversion to alkyl halide\" width=\"600\" height=\"319\" \/><\/h2>\n<p><strong>Table of Contents<\/strong><\/p>\n<ol>\n<li><a href=\"#one\">Making Alcohols Into Good Leaving Groups, Part 3<\/a><\/li>\n<li><a href=\"#two\">Why Do We Need Yet Another Method? (Hint: Grignard Formation)<\/a><\/li>\n<li><a href=\"#three\">Phosphorus Tribromide (PBr<sub>3<\/sub>) and Thionyl Chloride (SOCl<sub>2<\/sub>)<\/a><\/li>\n<li><a href=\"#four\">PBr<sub>3<\/sub> For Converting Alcohols To Alkyl Bromides: The Mechanism<\/a><\/li>\n<li><a href=\"#five\">SOCl<sub>2<\/sub> For Converting Alcohols To Alkyl Chlorides: The Mechanism<\/a><\/li>\n<li><a href=\"#six\">Summary: PBr<sub>3<\/sub> and SOCl2<\/a><\/li>\n<li><a href=\"#notes\">Notes<\/a><\/li>\n<li><a href=\"#quizzes\">Quiz Yourself!\u00a0<\/a><\/li>\n<li><a href=\"#references\">(Advanced) References and Further Reading<\/a><\/li>\n<\/ol>\n<hr \/>\n<h2><a id=\"one\"><\/a>1. Making Alcohols Into Good Leaving Groups, Part Three.<\/h2>\n<p><span style=\"color: #993366;\"><em>[Before we get too far into this, let me say that there&#8217;s some differences as to how the mechanism of the reaction of SOCl<sub>2<\/sub> with alcohols is taught. <strong>Most schools teach inversion<\/strong>, but it is also (rarely) taught as retention via a different mechanism. For the whole discussion, see this article: <a href=\"https:\/\/www.masterorganicchemistry.com\/2014\/02\/10\/socl2-and-the-sni-mechanism\/\">SOCl<sub>2<\/sub> and the S<sub>N<\/sub>i mechanism <\/a><\/em><\/span><\/p>\n<p>So far we\u2019ve covered two different ways of making alcohols into good leaving groups.<\/p>\n<p>&#8211; <strong>Conversion of <a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/02\/27\/making-alkyl-halides-from-alcohols\/\">alcohols to alkyl halides with strong acid<\/a><\/strong>. This works well for tertiary alcohols when nothing &#8220;bad&#8221; can happen (i.e. no side reactions). However, when certain secondary alcohols are used, <strong>rearrangements can occur.<\/strong><\/p>\n<p>&#8211; <strong>Conversion of alcohols into <a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/03\/10\/tosylates-and-mesylates\/\">tosylates or mesylates<\/a><\/strong>\u00a0&#8211; here, we break O-H and &#8220;cap&#8221; the oxygen with a &#8220;sulfonyl&#8221; group (&#8220;tosyl&#8221; and &#8220;mesyl&#8221; are popular choices). Very simple. No rearrangements. \u00a0\u00a0<strong>This does not affect<\/strong><strong>\u00a0the stereochemistry<\/strong>.<\/p>\n<p><img decoding=\"async\" class=\"alignnone wp-image-15206\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/1-converting-alcohols-to-alkyl-chlorides-works-ok-when-rearrangements-are-not-possible-but-when-they-are-it-is-better-to-use-a-different-strategy-like-converting-to-sulfonate-mesylate.gif\" alt=\"converting alcohols to alkyl chlorides works ok when rearrangements are not possible but when they are it is better to use a different strategy like converting to sulfonate mesylate\" width=\"600\" height=\"195\" \/><\/p>\n<h2><strong><a id=\"two\"><\/a>2. So why might we need more than these two ways to make alcohols to good leaving groups? Isn&#8217;t two methods enough?\u00a0<\/strong><\/h2>\n<p>Fair question!<\/p>\n<p>We mentioned that strong acid (HCl, HBr, HI) can lead to rearrangements with certain secondary alcohols. So an alternative that doesn&#8217;t lead to rearrangements would be useful from that perspective.\u00a0Secondly, <strong>strong acid is a pretty blunt instrument, like a sledgehammer<\/strong>. It gets the job done, but can lead to some collateral damage if you have a molecule containing functional groups with\u00a0various levels of acid sensitivity (esters, alkenes, alkynes). Using a milder, more targeted reagent would help us avoid undesired side reactions in more complex situations.<\/p>\n<p>A harder point to address is this: why not just, for example, always make alcohols into mesylates or tosylates if we want to make them good leaving groups? This is actually a great idea most of the time! \u00a0As for exceptions, I can think of at least one situation where when you would\u00a0<strong>need<\/strong> to make a halide.\u00a0For example, if you haven\u2019t already, you will learn about <a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/10\/14\/reagent-friday-grignard-reagents\/\"><strong>Grignard reagents<\/strong><\/a> at some point. <strong>These can be made from alkyl halides but not from mesylates or tosylates<\/strong>, so an alternative to what we&#8217;ve already learned is good to know.<\/p>\n<p>OK. Let&#8217;s dig in.<\/p>\n<h2><a id=\"three\"><\/a>3. Phosphorus Tribromide (PBr<sub>3<\/sub>) and Thionyl Chloride (SOCl<sub>2<\/sub>)<\/h2>\n<p>The reagents we&#8217;ll talk about today are thionyl chloride (SOCl<sub>2<\/sub>) and phosphorus tribromide (PBr<sub>3<\/sub>). These are two representatives of a family [<a href=\"#noteone\">Note 1<\/a>] of reagents that can convert alcohols to alkyl halides (<span style=\"color: #993366;\"><em>Later on, when you learn about carboxylic acids, you&#8217;ll see that these can also be used to convert carboxylic acids to acyl halides<\/em><\/span>).<\/p>\n<p>Here&#8217;s examples of each of these reagents in action.<\/p>\n<p><img decoding=\"async\" class=\"alignnone wp-image-15207\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/2-use-of-pbr3-and-socl2-to-convert-alcohols-to-alkyl-halides-occurs-with-inversion-of-configuration.gif\" alt=\"use of pbr3 and socl2 to convert alcohols to alkyl halides occurs with inversion of configuration\" width=\"600\" height=\"202\" \/><\/p>\n<p>What do you notice?<\/p>\n<ul>\n<li>First of all, check out the bonds formed and bonds broken: break C-OH, form C-Br or C-Cl<\/li>\n<li>Note the\u00a0<strong>change in stereochemistry<\/strong>. Both occur with inversion.<\/li>\n<li>Note the\u00a0<strong>lack of rearrangement.\u00a0<\/strong>Had we used HCl or HBr, it would have led to a ring expansion.<\/li>\n<\/ul>\n<p>Nice and clean way to convert alcohols to alkyl halides.<\/p>\n<h2><a id=\"four\"><\/a>4. PBr<sub>3<\/sub> For Converting Alcohols To Alkyl Halides: Mechanism<\/h2>\n<p>So how do they work? Let&#8217;s look at PBr<sub>3<\/sub>.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15208\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/3-mechanism-of-converting-alcohol-to-alkyl-bromide-using-pbr3-alcohol-attacks-phosphorus-then-bromide-does-backside-attack-giving-inversion.gif\" alt=\"mechanism of converting alcohol to alkyl bromide using pbr3 alcohol attacks phosphorus then bromide does backside attack giving inversion\" width=\"600\" height=\"286\" \/><\/p>\n<p>This reaction proceeds in two steps that you can think of as &#8220;activation&#8221; and &#8220;substitution&#8221;. In the &#8220;activation&#8221; step, \u00a0the alcohol is converted into a good leaving group by forming a bond to P (O-P bonds are very strong) and displacing Br from P<span style=\"color: #993366;\"><em> [note that this is essentially nucleophilic substitution at phosphorus].<\/em><\/span><\/p>\n<p>Now that the oxygen has been &#8220;activated&#8221; (i.e. converted to a good leaving group) a <strong>substitution<\/strong> reaction at carbon can occur.<\/p>\n<p>The <strong>bromide ion<\/strong> that was displaced from phosphorus <strong>attacks carbon<\/strong> via backside attack (S<sub>N<\/sub>2), forming C-Br and breaking C-O and we are left with a new <strong>alkyl bromide<\/strong> (with inversion of configuration) and the Br<sub>2<\/sub>P-OH leaving group.<\/p>\n<h2><a id=\"five\"><\/a>5. SOCl<sub>2<\/sub> For Converting Alcohols To Alkyl Chlorides: Mechanism<\/h2>\n<p>The reaction of thionyl chloride with alcohols similarly goes through an &#8220;activation&#8221; step and a &#8220;substitution&#8221; step. In the first step, oxygen attacks sulfur, displacing chloride ion. In the second step the chloride ion attacks carbon in an SN2 reaction, leading to inversion of configuration. [<a href=\"#notetwo\">Note 2<\/a>]<\/p>\n<p>For our purposes, the mechanism ends here, but it&#8217;s worth noting that the sulfur byproduct (HO-S(O)-Cl) can further break down to SO<sub>2<\/sub> gas and HCl through the mechanism shown [<span style=\"color: #993366;\"><em>similar to the breakdown of <a style=\"color: #993366;\" href=\"http:\/\/en.wikipedia.org\/wiki\/Carbonic_acid\">carbonic acid<\/a> to CO<sub>2<\/sub> and water<\/em><\/span>]. Removal of SO<sub>2<\/sub>\u00a0from the reaction vessel renders this reaction irreversible and helps drive the reaction to completion.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15209\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/4-mechanism-of-thionyl-chloride-socl2-with-secondary-alcohol-first-attack-at-sulfur-displacing-chloride-which-then-performs-sn2-giving-inversion.gif\" alt=\"mechanism of thionyl chloride socl2 with secondary alcohol first attack at sulfur displacing chloride which then performs sn2 giving inversion\" width=\"600\" height=\"293\" \/><\/p>\n<p><span style=\"color: #993366;\"><em>[I recall TA&#8217;ing a lab where a student dropped a round bottom flask with 5 mL of SOCl<sub>2<\/sub> into a rotovap bath &#8211; there was immediate bubbling and the stench of SO<sub>2<\/sub> made us have to evacuate the entire lab of about 120 people outside for fresh air. We were lucky it was a pleasant day and not\u00a0in the depths of Montreal&#8217;s epic winters]<\/em><\/span><\/p>\n<p>The process shown works well for primary and secondary alcohols. A process that goes through an S<sub>N<\/sub>2 mechanism shouldn&#8217;t work so well for tertiary alcohols. \u00a0I find textbooks extremely vague as to how they cover the use of these reagents with tertiary alcohols, so I&#8217;m not going to go into more detail on this point. [<a href=\"#notethree\">Note 3<\/a>]. Ask your instructor.<\/p>\n<h2><a id=\"six\"><\/a>6. Summary: PBr<sub>3<\/sub> and SOCl<sub>2<\/sub><\/h2>\n<p>The bottom line for today is to learn about these two methods for converting alcohols into alkyl halides, <strong>and pay particular attention to their stereochemistry. Extremely testable!\u00a0<\/strong><\/p>\n<p>I think that&#8217;s about all we have to say about converting alcohols to good leaving groups!<\/p>\n<p>There&#8217;s just one more thing here. We&#8217;ve\u00a0finished covering\u00a0substitution reactions of alcohols. But what about\u00a0<strong>elimination<\/strong> reactions of alcohols? How would we go about making alkenes? (aka &#8220;dehydration&#8221;). Many of the steps will look familiar &#8211; but there will be new wrinkles too.<\/p>\n<p><strong>Next Post &#8211; <a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/\">Elimination Reactions Of Alcohols<\/a><\/strong><\/p>\n<hr \/>\n<h2><a id=\"notes\"><\/a>Notes<\/h2>\n<div class=\"related-articles\"><p><strong>Related Articles<\/strong><\/p><ul><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/04\/16\/elimination-reactions-of-alcohols\/\" class=\"\"><span>Elimination Reactions of Alcohols<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/03\/10\/tosylates-and-mesylates\/\" class=\"\"><span>Tosylates And Mesylates<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/02\/27\/making-alkyl-halides-from-alcohols\/\" class=\"\"><span>Making Alkyl Halides From Alcohols<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/04\/12\/what-makes-a-good-leaving-group\/\" class=\"\"><span>What makes a good leaving group?<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2014\/02\/10\/socl2-and-the-sni-mechanism\/\" class=\"\"><span>SOCl2 Mechanism For Alcohols To Alkyl Halides: SN2 versus SNi<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2012\/08\/07\/the-conjugate-acid-is-a-better-leaving-group\/\" class=\"\"><span>The Conjugate Acid Is A Better Leaving Group<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2012\/07\/04\/the-sn2-mechanism\/\" class=\"\"><span>The SN2 Mechanism<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2015\/12\/10\/reactions-of-grignard-reagents\/\" class=\"\"><span>Reactions of Grignard Reagents<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/12\/03\/reagent-friday-thionyl-chloride-socl2\/\" class=\"\"><span>Thionyl Chloride (SOCl2)<\/span><\/a><\/li><\/ul><\/div>\n<p><strong><a id=\"noteone\"><\/a>Note 1. <\/strong>By family of reagents, I mean that there are related reagents that go through the same mechanisms , that we won&#8217;t talk about today (PCl<sub>3<\/sub>, SOBr<sub>2<\/sub>, PCl<sub>5<\/sub>, PBr<sub>5<\/sub>)<\/p>\n<p><strong><a id=\"notetwo\"><\/a>Note 2. <\/strong>Again, things in &#8220;real life&#8221; are a bit more complicated. You might want to double check that your instructor follows this mechanism. If not, check out this post on the SNi mechanism.<\/p>\n<p><strong><a id=\"notethree\"><\/a>Note 3. <\/strong>\u00a0<a href=\"https:\/\/www.amazon.com\/Marchs-Advanced-Organic-Chemistry-Mechanisms\/dp\/0470462590\">March<\/a> mentions that SOCl<sub>2<\/sub> can be used to\u00a0convert tertiary alcohols to tertiary alkyl chlorides. So &#8220;in the lab&#8221;, things are a bit more complex than alluded to here.<\/p>\n<hr \/>\n<h2><a id=\"quizzes\"><\/a>Quiz Yourself!<\/h2>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/1357-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/1359-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/1341-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/1342-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/1343-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n<hr \/>\n<h2><strong><a id=\"references\"><\/a>(Advanced) References and Further Reading<\/strong><\/h2>\n<p>The conversion of alcohols into alkyl bromides with PBr<sub>3<\/sub> is quite general. The reaction conditions for this are varied, and all 3 bromine atoms in PBr<sub>3<\/sub> are available for reaction.<\/p>\n<ol>\n<li><strong>Convenient synthesis of labile optically active secondary alkyl bromides from chiral alcohols<br \/>\n<\/strong>Robert O. Hutchins, Divakar. Masilamani, and Cynthia A. Maryanoff<br \/>\n<em>The Journal of Organic Chemistry<\/em><strong> 1976, <\/strong><em>41<\/em> (6), 1071-1073<br \/>\n<strong>DOI: <\/strong><a href=\"https:\/\/pubs.acs.org\/doi\/abs\/10.1021\/jo00868a034\">10.1021\/jo00868a034<\/a><\/li>\n<li><strong>Synthesis of Optically Active Alkyl Halides<\/strong><br \/>\nHarry R. Hudson<br \/>\n<em>Synthesis<\/em> <strong>1969<\/strong>, 112-119<br \/>\n<strong>DOI:<\/strong> <a href=\"https:\/\/www.thieme-connect.com\/products\/ejournals\/abstract\/10.1055\/s-1969-34195\">10.1055\/s-1969-34195<\/a><br \/>\nThe main utility of PBr<sub>3<\/sub> is that it allows the conversion of chiral alcohols to bromides with <em>retention of configuration<\/em>, as the above two papers demonstrate. They also illustrate the mechanism of the reaction, going through the intermediate alkyl phosphites.<\/li>\n<li><strong>TETRAHYDROFURFURYL BROMIDE<br \/>\nH. Smith<br \/>\n<\/strong><em>Org. Synth.<\/em><strong> 1943, <\/strong><em>23<\/em>, 88<br \/>\nDOI: <a href=\"http:\/\/www.orgsyn.org\/demo.aspx?prep=CV3P0793\">10.15227\/orgsyn.023.0088<\/a><br \/>\nThis procedure from <em>Organic Synthesis<\/em>, a source of reliable and independently tested experimental organic chemistry procedures, shows how PBr<sub>3<\/sub> is compatible with ethers.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>PBr3 and SOCl2: Reagents For Converting Alcohols To Good Leaving Groups Alcohols can be converted into alkyl halides with phosphorus tribromide (PBr3) or thionyl chloride <\/p>\n","protected":false},"author":1,"featured_media":15205,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1420],"tags":[167,301,226,1057,239,1056,293,300,279,1058],"post_folder":[],"class_list":["post-8823","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-alcohols-epoxides-ethers","tag-alcohols","tag-inversion","tag-leaving-groups","tag-mesylates","tag-mscl","tag-pbr3","tag-rearrangements","tag-socl2","tag-substitution","tag-tosylates"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>PBr3 and SOCl2 &#8211; Master Organic Chemistry<\/title>\n<meta name=\"description\" content=\"Phosphorus tribromide (PBr3) and thionyl chloride (SOCl2) are useful reagents for converting alcohols to alkyl halides. Watch out for the stereochemistry!\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"PBr3 and SOCl2 &#8211; Master Organic Chemistry\" \/>\n<meta property=\"og:description\" content=\"Phosphorus tribromide (PBr3) and thionyl chloride (SOCl2) are useful reagents for converting alcohols to alkyl halides. Watch out for the stereochemistry!\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/\" \/>\n<meta property=\"og:site_name\" content=\"Master Organic Chemistry\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/Master-Organic-Chemistry-242610599108055\/\" \/>\n<meta property=\"article:published_time\" content=\"2015-03-20T17:39:08+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-05-14T18:05:06+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif\" \/>\n\t<meta property=\"og:image:width\" content=\"880\" \/>\n\t<meta property=\"og:image:height\" content=\"468\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/gif\" \/>\n<meta name=\"author\" content=\"James Ashenhurst\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"James Ashenhurst\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"8 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/\"},\"author\":{\"name\":\"James Ashenhurst\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/person\\\/78d83ec7d02b4b7365bade2cedaef80c\"},\"headline\":\"PBr3 and SOCl2\",\"datePublished\":\"2015-03-20T17:39:08+00:00\",\"dateModified\":\"2025-05-14T18:05:06+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/\"},\"wordCount\":1499,\"commentCount\":22,\"publisher\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/12\\\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif\",\"keywords\":[\"alcohols\",\"inversion\",\"leaving groups\",\"mesylates\",\"MsCl\",\"pbr3\",\"rearrangements\",\"socl2\",\"substitution\",\"tosylates\"],\"articleSection\":[\"Alcohols, Epoxides and Ethers\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/\",\"name\":\"PBr3 and SOCl2 &#8211; Master Organic Chemistry\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/12\\\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif\",\"datePublished\":\"2015-03-20T17:39:08+00:00\",\"dateModified\":\"2025-05-14T18:05:06+00:00\",\"description\":\"Phosphorus tribromide (PBr3) and thionyl chloride (SOCl2) are useful reagents for converting alcohols to alkyl halides. Watch out for the stereochemistry!\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/#primaryimage\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/12\\\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif\",\"contentUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/12\\\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif\",\"width\":880,\"height\":468,\"caption\":\"summary of pbr3 phosphorus tribromide and socl2 thionyl chloride both result in inversion of configuration of alcohol conversion to alkyl halide\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2015\\\/03\\\/20\\\/pbr3-and-socl2\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"PBr3 and SOCl2\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#website\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/\",\"name\":\"Master Organic Chemistry\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#organization\",\"name\":\"Master Organic Chemistry\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/04\\\/cutmypic.png\",\"contentUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/04\\\/cutmypic.png\",\"width\":225,\"height\":225,\"caption\":\"Master Organic Chemistry\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/Master-Organic-Chemistry-242610599108055\\\/\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/person\\\/78d83ec7d02b4b7365bade2cedaef80c\",\"name\":\"James Ashenhurst\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g\",\"caption\":\"James Ashenhurst\"},\"description\":\"Ph.D. 2006, McGill University (James L. Gleason). Postdoctoral Associate, 2008-2010, Massachusetts Institute of Technology (M. Movassaghi). Founder, Master Organic Chemistry, 2010-present.\",\"sameAs\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/about\\\/\"],\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/author\\\/james\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"PBr3 and SOCl2 &#8211; Master Organic Chemistry","description":"Phosphorus tribromide (PBr3) and thionyl chloride (SOCl2) are useful reagents for converting alcohols to alkyl halides. Watch out for the stereochemistry!","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/","og_locale":"en_US","og_type":"article","og_title":"PBr3 and SOCl2 &#8211; Master Organic Chemistry","og_description":"Phosphorus tribromide (PBr3) and thionyl chloride (SOCl2) are useful reagents for converting alcohols to alkyl halides. Watch out for the stereochemistry!","og_url":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/","og_site_name":"Master Organic Chemistry","article_publisher":"https:\/\/www.facebook.com\/Master-Organic-Chemistry-242610599108055\/","article_published_time":"2015-03-20T17:39:08+00:00","article_modified_time":"2025-05-14T18:05:06+00:00","og_image":[{"width":880,"height":468,"url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif","type":"image\/gif"}],"author":"James Ashenhurst","twitter_card":"summary_large_image","twitter_misc":{"Written by":"James Ashenhurst","Est. reading time":"8 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/#article","isPartOf":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/"},"author":{"name":"James Ashenhurst","@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/person\/78d83ec7d02b4b7365bade2cedaef80c"},"headline":"PBr3 and SOCl2","datePublished":"2015-03-20T17:39:08+00:00","dateModified":"2025-05-14T18:05:06+00:00","mainEntityOfPage":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/"},"wordCount":1499,"commentCount":22,"publisher":{"@id":"https:\/\/www.masterorganicchemistry.com\/#organization"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/#primaryimage"},"thumbnailUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif","keywords":["alcohols","inversion","leaving groups","mesylates","MsCl","pbr3","rearrangements","socl2","substitution","tosylates"],"articleSection":["Alcohols, Epoxides and Ethers"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/","url":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/","name":"PBr3 and SOCl2 &#8211; Master Organic Chemistry","isPartOf":{"@id":"https:\/\/www.masterorganicchemistry.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/#primaryimage"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/#primaryimage"},"thumbnailUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif","datePublished":"2015-03-20T17:39:08+00:00","dateModified":"2025-05-14T18:05:06+00:00","description":"Phosphorus tribromide (PBr3) and thionyl chloride (SOCl2) are useful reagents for converting alcohols to alkyl halides. Watch out for the stereochemistry!","breadcrumb":{"@id":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/#primaryimage","url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif","contentUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-pbr3-phosphorus-tribromide-and-socl2-thionyl-chloride-both-result-in-inversion-of-configuration-of-alcohol-conversion-to-alkyl-halide.gif","width":880,"height":468,"caption":"summary of pbr3 phosphorus tribromide and socl2 thionyl chloride both result in inversion of configuration of alcohol conversion to alkyl halide"},{"@type":"BreadcrumbList","@id":"https:\/\/www.masterorganicchemistry.com\/2015\/03\/20\/pbr3-and-socl2\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.masterorganicchemistry.com\/"},{"@type":"ListItem","position":2,"name":"PBr3 and SOCl2"}]},{"@type":"WebSite","@id":"https:\/\/www.masterorganicchemistry.com\/#website","url":"https:\/\/www.masterorganicchemistry.com\/","name":"Master Organic Chemistry","description":"","publisher":{"@id":"https:\/\/www.masterorganicchemistry.com\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.masterorganicchemistry.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.masterorganicchemistry.com\/#organization","name":"Master Organic Chemistry","url":"https:\/\/www.masterorganicchemistry.com\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/logo\/image\/","url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/04\/cutmypic.png","contentUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/04\/cutmypic.png","width":225,"height":225,"caption":"Master Organic Chemistry"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/Master-Organic-Chemistry-242610599108055\/"]},{"@type":"Person","@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/person\/78d83ec7d02b4b7365bade2cedaef80c","name":"James Ashenhurst","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g","caption":"James Ashenhurst"},"description":"Ph.D. 2006, McGill University (James L. Gleason). Postdoctoral Associate, 2008-2010, Massachusetts Institute of Technology (M. Movassaghi). Founder, Master Organic Chemistry, 2010-present.","sameAs":["https:\/\/www.masterorganicchemistry.com\/about\/"],"url":"https:\/\/www.masterorganicchemistry.com\/author\/james\/"}]}},"_links":{"self":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/posts\/8823","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/comments?post=8823"}],"version-history":[{"count":0,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/posts\/8823\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/media\/15205"}],"wp:attachment":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/media?parent=8823"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/categories?post=8823"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/tags?post=8823"},{"taxonomy":"post_folder","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/post_folder?post=8823"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}