Alternate Method for the Synthesis of N‐Alkyl/aralkyl‐2‐(α‐hydroxy Alkyl/aralkyl)benzimidazoles via Regiospecific Acetylation
摘要:
Acetylation of 1H-2-(alpha-hydroxyalkyl/aryl) benzimidazoles 2 with Ac2O results in the regiospecific formation of O-acetoxy derivative 3, which on alkylation with alkylating agents in nonaqueous media under phase-transfer catalytic conditions affords N-alkyl derivatives 4. The latter, on hydrolysis in an aqueous basic medium, results in the title compounds 5 in good yields in high purity. Alternatively, 5 can also be obtained by reduction of 1-substituted-2-acetyl/benzoylbenzimidazoles 8 using NaBH4.
Alternate Method for the Synthesis of N‐Alkyl/aralkyl‐2‐(α‐hydroxy Alkyl/aralkyl)benzimidazoles via Regiospecific Acetylation
摘要:
Acetylation of 1H-2-(alpha-hydroxyalkyl/aryl) benzimidazoles 2 with Ac2O results in the regiospecific formation of O-acetoxy derivative 3, which on alkylation with alkylating agents in nonaqueous media under phase-transfer catalytic conditions affords N-alkyl derivatives 4. The latter, on hydrolysis in an aqueous basic medium, results in the title compounds 5 in good yields in high purity. Alternatively, 5 can also be obtained by reduction of 1-substituted-2-acetyl/benzoylbenzimidazoles 8 using NaBH4.
Alternate Method for the Synthesis of N‐Alkyl/aralkyl‐2‐(α‐hydroxy Alkyl/aralkyl)benzimidazoles via Regiospecific Acetylation
作者:P. K. Dubey、P.V.V. Prasada Reddy、K. Srinivas
DOI:10.1080/00397910701265556
日期:2007.5.1
Acetylation of 1H-2-(alpha-hydroxyalkyl/aryl) benzimidazoles 2 with Ac2O results in the regiospecific formation of O-acetoxy derivative 3, which on alkylation with alkylating agents in nonaqueous media under phase-transfer catalytic conditions affords N-alkyl derivatives 4. The latter, on hydrolysis in an aqueous basic medium, results in the title compounds 5 in good yields in high purity. Alternatively, 5 can also be obtained by reduction of 1-substituted-2-acetyl/benzoylbenzimidazoles 8 using NaBH4.