{"id":3102,"date":"2019-01-09T09:58:44","date_gmt":"2019-01-09T09:58:44","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/?post_type=chapter&#038;p=3102"},"modified":"2019-01-09T10:03:57","modified_gmt":"2019-01-09T10:03:57","slug":"23-3-reactions-of-amines","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/chapter\/23-3-reactions-of-amines\/","title":{"raw":"23.3. Reactions of amines","rendered":"23.3. Reactions of amines"},"content":{"raw":"<div class=\"mw-parser-output\">\r\n<h2><span id=\"Amide_formation\" class=\"mw-headline\">Amide formation<\/span><\/h2>\r\nAcyl chlorides and acid anhydrides react with primary and secondary amines without the presence of heat to form amides. Tertiary amines cannot be acylated due to the absence of a replaceable hydrogen atom. With the much less active benzoyl chloride, acylation can still be performed by the use of excess aqueous base to facilitate the reaction.\r\n\r\n<img class=\"size-full wp-image-2503 aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3773\/2018\/11\/07205939\/512px-Amide_formation_from_amine.svg_.png\" alt=\"\" width=\"512\" height=\"157\" \/>\r\n<h2><span id=\"Salt_formation\" class=\"mw-headline\">Salt formation<\/span><\/h2>\r\nBecause amines are basic, they neutralize carboxylic acids to form the corresponding ammonium carboxylate salts. Upon heating to 200\u00b0C, the primary and secondary amine salts dehydrate to form the corresponding amides.\r\n<div class=\"center\"><img class=\"size-full wp-image-2504 aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3773\/2018\/11\/07210010\/Amine_plus_Carboxylic_Acid.png\" alt=\"\" width=\"548\" height=\"175\" \/><\/div>\r\n<h2><span id=\"Neutralization\" class=\"mw-headline\">Neutralization<\/span><\/h2>\r\nAmines R<sub>3<\/sub>N react with strong acids such as hydroiodic acid (HI), hydrobromic acid (HBr) and hydrochloric acid (HCl) to give ammonium salts R<sub>3<\/sub>NH<sup>+<\/sup>.\r\n<h2><span id=\"Reaction_with_nitrous_acid\" class=\"mw-headline\">Reaction with nitrous acid<\/span><\/h2>\r\nNitrous acid with the chemical formula HNO<sub>2<\/sub> is unstable. Usually it is produced indirectly in a mixture of NaNO<sub>2<\/sub> and a strong acid such as HCl or H<sub>2<\/sub>SO<sub>4<\/sub> in dilute concentration, so that the H<sup>+<\/sup> ions will associate with the NO<sub>2<\/sub><sup>-<\/sup> ions in solution.\r\n\r\nPrimary aliphatic amines with nitrous acid give very unstable diazonium salts which spontaneously decompose by losing N<sub>2<\/sub> to form a carbenium ion. The carbenium ion goes on to produce a mixture of alkenes, alkanols or alkyl halides, with alkanols as the major product. This reaction is of little synthetic importance because the diazonium salt formed is too unstable, even under quite cold conditions.\r\n<dl>\r\n \t<dd>NaNO<sub>2<\/sub> + HCl \u2192 HNO<sub>2<\/sub> + NaCl<\/dd>\r\n<\/dl>\r\n<div class=\"center\"><img class=\"size-full wp-image-2505 aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3773\/2018\/11\/07210048\/Nitrous_acid_with_n-amine.gif\" alt=\"\" width=\"631\" height=\"76\" \/><\/div>\r\n&nbsp;\r\n<ul>\r\n \t<li>Primary aromatic amines, such as aniline (phenylamine) forms a more stable diazonium ion at 0\u20135\u00b0C. Above 5\u00b0C, it will decompose to give phenol and N<sub>2<\/sub>. Diazonium salts can be isolated in the crystalline form but are usually used in solution and immediately after preparation, due to rapid decomposition on standing even with little ambient heat. Solid diazonium salts can be explosive on shock or on mild warming.<\/li>\r\n<\/ul>\r\n<img class=\"alignnone size-full wp-image-2506\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3773\/2018\/11\/07210118\/Aromatic_diazonium_salt.gif\" alt=\"\" width=\"404\" height=\"90\" \/>\r\n\r\n<\/div>\r\n<div class=\"mw-parser-output\">\r\n<h2><span id=\"Reactions_with_ketones_and_aldehydes\" class=\"mw-headline\">Reactions with ketones and aldehydes<\/span><\/h2>\r\n<ul>\r\n \t<li>Primary amines react with carbonyl compounds to form imines (see <a href=\"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/chapter\/21-4-imine-formation\/\">section 21.4.<\/a>). Specifically, aldehydes become aldimines, and ketones become ketimines. In the case of formaldehyde (R' = H), the imine products are typically cyclic trimers.<\/li>\r\n<\/ul>\r\n<dl>\r\n \t<dd>RNH<sub>2<\/sub> + R'<sub>2<\/sub>C=O \u2192 R'<sub>2<\/sub>C=NR + H<sub>2<\/sub>O<\/dd>\r\n<\/dl>\r\n<ul>\r\n \t<li>Secondary amines react with ketones and aldehydes to form enamines. An enamine contains a C=C double bond, where the second C is singly bonded to N as part of an amine ligand.<\/li>\r\n<\/ul>\r\n<dl>\r\n \t<dd>R<sub>2<\/sub>NH + R'(R\"CH<sub>2<\/sub>)C=O \u2192 R\"CH=C(NR<sub>2<\/sub>)R' + H<sub>2<\/sub>O<\/dd>\r\n<\/dl>\r\n<\/div>","rendered":"<div class=\"mw-parser-output\">\n<h2><span id=\"Amide_formation\" class=\"mw-headline\">Amide formation<\/span><\/h2>\n<p>Acyl chlorides and acid anhydrides react with primary and secondary amines without the presence of heat to form amides. Tertiary amines cannot be acylated due to the absence of a replaceable hydrogen atom. With the much less active benzoyl chloride, acylation can still be performed by the use of excess aqueous base to facilitate the reaction.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-2503 aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3773\/2018\/11\/07205939\/512px-Amide_formation_from_amine.svg_.png\" alt=\"\" width=\"512\" height=\"157\" \/><\/p>\n<h2><span id=\"Salt_formation\" class=\"mw-headline\">Salt formation<\/span><\/h2>\n<p>Because amines are basic, they neutralize carboxylic acids to form the corresponding ammonium carboxylate salts. Upon heating to 200\u00b0C, the primary and secondary amine salts dehydrate to form the corresponding amides.<\/p>\n<div class=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-2504 aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3773\/2018\/11\/07210010\/Amine_plus_Carboxylic_Acid.png\" alt=\"\" width=\"548\" height=\"175\" \/><\/div>\n<h2><span id=\"Neutralization\" class=\"mw-headline\">Neutralization<\/span><\/h2>\n<p>Amines R<sub>3<\/sub>N react with strong acids such as hydroiodic acid (HI), hydrobromic acid (HBr) and hydrochloric acid (HCl) to give ammonium salts R<sub>3<\/sub>NH<sup>+<\/sup>.<\/p>\n<h2><span id=\"Reaction_with_nitrous_acid\" class=\"mw-headline\">Reaction with nitrous acid<\/span><\/h2>\n<p>Nitrous acid with the chemical formula HNO<sub>2<\/sub> is unstable. Usually it is produced indirectly in a mixture of NaNO<sub>2<\/sub> and a strong acid such as HCl or H<sub>2<\/sub>SO<sub>4<\/sub> in dilute concentration, so that the H<sup>+<\/sup> ions will associate with the NO<sub>2<\/sub><sup>&#8211;<\/sup> ions in solution.<\/p>\n<p>Primary aliphatic amines with nitrous acid give very unstable diazonium salts which spontaneously decompose by losing N<sub>2<\/sub> to form a carbenium ion. The carbenium ion goes on to produce a mixture of alkenes, alkanols or alkyl halides, with alkanols as the major product. This reaction is of little synthetic importance because the diazonium salt formed is too unstable, even under quite cold conditions.<\/p>\n<dl>\n<dd>NaNO<sub>2<\/sub> + HCl \u2192 HNO<sub>2<\/sub> + NaCl<\/dd>\n<\/dl>\n<div class=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-2505 aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3773\/2018\/11\/07210048\/Nitrous_acid_with_n-amine.gif\" alt=\"\" width=\"631\" height=\"76\" \/><\/div>\n<p>&nbsp;<\/p>\n<ul>\n<li>Primary aromatic amines, such as aniline (phenylamine) forms a more stable diazonium ion at 0\u20135\u00b0C. Above 5\u00b0C, it will decompose to give phenol and N<sub>2<\/sub>. Diazonium salts can be isolated in the crystalline form but are usually used in solution and immediately after preparation, due to rapid decomposition on standing even with little ambient heat. Solid diazonium salts can be explosive on shock or on mild warming.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2506\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3773\/2018\/11\/07210118\/Aromatic_diazonium_salt.gif\" alt=\"\" width=\"404\" height=\"90\" \/><\/p>\n<\/div>\n<div class=\"mw-parser-output\">\n<h2><span id=\"Reactions_with_ketones_and_aldehydes\" class=\"mw-headline\">Reactions with ketones and aldehydes<\/span><\/h2>\n<ul>\n<li>Primary amines react with carbonyl compounds to form imines (see <a href=\"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/chapter\/21-4-imine-formation\/\">section 21.4.<\/a>). Specifically, aldehydes become aldimines, and ketones become ketimines. In the case of formaldehyde (R&#8217; = H), the imine products are typically cyclic trimers.<\/li>\n<\/ul>\n<dl>\n<dd>RNH<sub>2<\/sub> + R&#8217;<sub>2<\/sub>C=O \u2192 R&#8217;<sub>2<\/sub>C=NR + H<sub>2<\/sub>O<\/dd>\n<\/dl>\n<ul>\n<li>Secondary amines react with ketones and aldehydes to form enamines. An enamine contains a C=C double bond, where the second C is singly bonded to N as part of an amine ligand.<\/li>\n<\/ul>\n<dl>\n<dd>R<sub>2<\/sub>NH + R'(R&#8221;CH<sub>2<\/sub>)C=O \u2192 R&#8221;CH=C(NR<sub>2<\/sub>)R&#8217; + H<sub>2<\/sub>O<\/dd>\n<\/dl>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-3102\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Organic Chemistry\/Amines. <strong>Authored by<\/strong>: Wikibooks contributors. <strong>Provided by<\/strong>: Wikibooks. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/en.wikibooks.org\/wiki\/Organic_Chemistry\/Amines\">https:\/\/en.wikibooks.org\/wiki\/Organic_Chemistry\/Amines<\/a>. <strong>Project<\/strong>: Book: Organic Chemistry. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":96103,"menu_order":4,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Organic Chemistry\/Amines\",\"author\":\"Wikibooks contributors\",\"organization\":\"Wikibooks\",\"url\":\"https:\/\/en.wikibooks.org\/wiki\/Organic_Chemistry\/Amines\",\"project\":\"Book: Organic Chemistry\",\"license\":\"cc-by-sa\",\"license_terms\":\"\"}]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-3102","chapter","type-chapter","status-publish","hentry"],"part":2180,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapters\/3102","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/wp\/v2\/users\/96103"}],"version-history":[{"count":4,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapters\/3102\/revisions"}],"predecessor-version":[{"id":3105,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapters\/3102\/revisions\/3105"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/parts\/2180"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapters\/3102\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/wp\/v2\/media?parent=3102"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapter-type?post=3102"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/wp\/v2\/contributor?post=3102"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/wp\/v2\/license?post=3102"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}