- An improved and convenient procedure for the synthesis of 1-substituted imidazoles
-
1-Protected imidazoles, such as 1-acetyl- and 1-benzoylimidazoles, react with various halides, such as benzyl, allyl, α-keto, and alkyl halides, to give 1-protected-3-substituted imidazolium salts in high yields. The resultant imidazolium salts are easily deprotected by treatment with water or alcohols to give the corresponding 1-substituted imidazoles in excellent yields. In this reaction the yields of 1-substituted imidazoles vary with the kinds of halides used and/or with the protecting groups, and the yields increase in the following order: benzyl halides≥allyl halides~α-keto halides>alkyl halides, and acetyl≥benzoyl>ethoxycarbonyl>diethoxymethyl>trimethylsilyl>tosyl.
- Kamijo,Yamamoto,Harada,Iizuka
-
-
Read Online
- 1-ACYL-3-SUBSTITUTED IMIDAZOLIUM SALTS AS HIGHLY REACTIVE ACYLATING AGENTS
-
1-Acylimidazoles could be highly activated for acylation by the quarternizing with benzyl halides. 1-Acyl-3-benzylimidazolium halides were powerful acylating agents.Alcohols, phenols, and amines were converted to the corresponding esters and amides in excellent yields under mild conditions.Keywords - 1-acyl-3-substituted imidazolium salts; acylating agents; 1-acylimidazoles; 1-acetyl-3-benzylimidazolium bromide; 1-benzoyl-3-benzylimidazolium bromide
- Kamijo, Tetsuhide,Yamamoto, Ryoji,Harada, Hiromu,Iizuka, Kinji
-
p. 4242 - 4244
(2007/10/02)
-