A METHOD FOR THE RAPID CLEAVAGE OF SULFONAMIDES
A METHOD FOR THE RAPID CLEAVAGE OF SULFONAMIDES
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DOI：
10.1021/ja01128a041
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发表时间：
1952-01-01
影响因子：
15
通讯作者：
HECKERT, RE
中科院分区：
文献类型：
--
作者：
SNYDER, HR;HECKERT, RE
A mixture of 48% hydrobromic acid and phenol is an excellent reagent for the rapid cleavage of a sulfonamide when the object is the recovery of the constituent amine. The cleavage is not a simple hydrolysis; an oxidation-reduction reaction between thesulfur-containing fragment and the hydrobromic acid is involved. The phenol serves not only to remove bro-mine from the reaction mixture, thereby preventing its reaction with the liberated amine, but also to increase the solubility of the sulfonamide.The foremost objection to the Hinsberg method8 for the separation of primary, secondary and tertiary amines has been the difficulty with which the intermediate sulfonamides are hydrolyzed. Although a number of attempts havebeen made to find conditions under which this hydrolysis would proceed rapidly and in good yield, none has been entirely satisfactory. In the present investigation, a mixture of 48% hydrobromicacid and phenol has been found to be an excellent reagent for cleaving sulfonamides when the object is the recovery of the constituent amines. The reagents commonly employed in theacid hydrolysis of sulfonamides are hydrochloric and sulfuric acids. Whereas sulfonamides are sparingly soluble in hydrochloric acid, they are usually soluble in strong sulfuric acid. Various concentrations of sulfuric acid4 and sulfuric and acetic acids5 have been used at moderate temperatures. Although satisfactory hydrolysis rates are normally observed, when aryl amines are produced in the hydrolysis the reaction is complicated by sulfonation. In concentrated sulfuric acid, the rearrange-ment of sulfonamides to amino-sulfonesmay also occur. 4”'6
