1H-Pyrrole-1-carboxamide, 3-ethyl-2,5-dihydro-4-methyl-N-2-4-(trans-4-methylcyclohexyl)aminocarbonylaminosulfonylphenylethyl-2-oxo- → [2-(3-Ethyl-4-methyl-2-carbonyl pyrrolidine amido)ethyl]benzene

関与物質

反応手順

U.S. Pat. No. 4,379,785 (hereinafter referred to as the '785 patent) discloses heterocyclic substituted sulfonylureas, particularly N-[4-[2-(3-ethyl-4-methyl-2-oxo-3-pyrroline-1-carboxamido)-ethyl]-benzenesulfonyl]-N′-4-methylcyclohexylurea i.e. glimepiride. The '785 patent teaches the preparation of glimepiride starting from 3-Ethyl-4-methyl-3-pyrrolidin-2-one and 2-phenylethylisocyanate to give [2-(3-Ethyl-4-methyl-2-carbonyl pyrrolidine amido)ethyl]benzene. The [2-(3-Ethyl-4-methyl-2-carbonyl pyrrolidine amido)ethyl]benzene is converted to the 4-[2-(3-Ethyl-4-methyl-2-carbonyl pyrrolidine amido)ethyl]benzene sulfonamide, a compound of formula 4, by reacting with chlorosulfonic acid, followed by treatment with ammonia solution. This intermediate compound of formula 4 is further reacted with trans-4-methylyclohexyl isocyanate to form glimepiride. The '785 patent teaches a three step process for preparation of the intermediate compound of formula 4, i.e. 4-[2-(3-Ethyl-4-methyl-2-carbonyl pyrrolidine amido)ethyl]benzene sulfonamide, which is represented in Scheme 1.

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