Benzamidomethylation with (Benzamidomethyl)triethylammonium Chloride. 2. A Simple Method for Benzamidomethylation of Thiols, Amines and Carboxylic Acids
Thiols and amines were benzamidomethylated in water solution at room temperature with (benzamidomethyl)triethylammonium chloride (1) in the presence of a small quantity of triethylamine (pH>9). Benzamidomethyl thioethers (3a-d) and (benzamidomethyl) amines or di(benzamidomethyl)amines (5) were obtained in high yields (>90%) as well as S(CH2NHBz)2 in a reaction of 1 with Na2S. Benzamidomethyl esters RCOOCH2NHBz were obtained (60-75%) in reactions of carboxylic acids with 1 in chloroform or dioxane.
An explanation for the failure of aminomethanesulfonic acid to form sulfonamides. Acyl chloride-promoted generation of α-carboxamidoalkylating electrophiles.
作者:Gregory R. Moe、Lawrence M. Sayre、Philip S. Portoghese
DOI:10.1016/s0040-4039(01)90148-0
日期:——
Attempted N,N-dibenzoylation of aminomethanesulfonicacid results in CS bond cleavage, generating synthetically useful α-benzamidomethylating electrophiles. The importance of this observation in regard to the reported failures to prepare sulfonamide analogs of peptides is discussed.
An expeditious synthesis for γ-carboline analogue 4-aryl-1,3-thiazino[6,5-b]indole derivatives via the trifluoromethanesulfonic acid-promoted isomerization of 3-amidomethylthioindole intermediates to 2-indolyl sulfides
A highly efficient trifluoromethanesulfonic acid-mediated rearrangement of the benzoylaminomethylthio group of 3-benzoylaminomethylthioindoles (7a-e) to position 2 of the indole ring was developed. Thus, 2-benzoylaminomethylthioindoles (9a-e) were obtained in good yields and were involved as key intermediates in the synthesis of the new gamma-carboline analogue ring system: 2,9-dihydro-4-aryl-1,3-thiazino[6,5-b]indole derivatives (11a-e). The target thiazinoindoles (11a-e) were prepared via 2-thiobenzoylaminomethylindoles (10a-e) in modified Bischler-Napieralski reactions. (C) 2008 Elsevier Ltd. All rights reserved.
Synthesis of 4-thiaharmalan analogue 4-aryl-1,3-thiazino[5,6-b]indole derivatives by prevention of rearrangements to position two of the indole moiety
An efficient and selective non-acidic protocol has been developed for the synthesis of derivatives of a new ring system: 4-aryl-1,3-thiazino[5,6-b]indole, a 4-thiaharmalan analogue. The convenient amidomethylation of indole-3-thiol (5) afforded 3-beilzoylaminomethyithio-1H-indole (7a). with orthoamidomethylated 2-benzoylamino-methyl-3-benzoylaminomethylthio-1H-indole (8) as side product. Following the Bischler-Napieralski reaction of 7a the rearranged 2-benzoylaminomethylthio-1H-indole 11 could be isolated. In order to prevent such rearrangements the target thiazinoindoles were prepared via 3-thiobenzoylanlinomethylthioindole (13) via a modified Bischler-Napieralski reaction. (c) 2008 Elsevier Ltd. All rights reserved.
Simple Method for Benzamidomethylation of Phenols in Water Solution
Benzamidomethyl ethers ROCH(2)NHBz (5) (R = aryl, cyclohexyl and benzyl) were obtained in high yields in reactions of ROH (4) with (benzamidomethyl)triethylammonium chloride 3 as a benzamidomethylation agent. Reactions occurred in water, except reactions of cyclohexyl and benzyl alcohol with 3 that occurred in CHCl3.