Tropic acid → cis-N-[2-[4-[(4-amino-5-chloro-2-methoxybenzoyl)amino]-3-methoxy-1-piperidinyl]ethyl]-alpha-(hydroxymethyl)benzeneacetamide

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Reaction Steps

To a stirred suspension of 2.99 parts of α-(hydroxymethyl)benzeneacetic acid in 60 parts of trichloromethane were added dropwise first 1.82 parts of N,N-diethylethanamine and then 1.95 parts of ethyl carbonochloridate at a temperature below 5° C. Upon completion, stirring was continued for 45 minutes at this low temperature. The thus obtained solution was added dropwise to a solution of 5.35 parts of cis-4-amino-N-[1-(2-aminoethyl)-3-methoxy-4-piperidinyl]-5-chloro-2-methoxybenzamide in 45 parts of trichloromethane while the temperature was kept below 10° C. Upon completion, the whole was stirred for 20 hours at room temperature. The organic layer was washed with a sodium carbonate solution in water and with water, dried, filtered and evaporated. The residue was purified by column chromatography over silicia gel using a mixture of trichloromethane and methanol, saturated with ammonia, (98:2 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from acetonitrile and a few drops of water. The product was filtered off and dried in vacuo at 30° C., yielding 0.76 parts (10.0%) of cis-N-[2-[4-[(4-amino-5-chloro-2-methoxybenzoyl)amino]-3-methoxy-1-piperidinyl]ethyl]-α-(hydroxymethyl)benzeneacetamide; mp. 114.0° C. (compound 87).

Provenance & Evidence