Ethyl chloroformate → Ethyl cis-4-[(4-amino-5-chloro-2,3-dihydro-2,2-dimethyl-7-benzofuranyl)carbonylamino]-3-methoxy-1-piperidinecarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 8.1 parts of 4-amino-5-chloro-2,3-dihydro-2,2-dimethyl-7-benzofurancarboxylic acid in 218 parts of trichloromethane and 3.43 parts of N,N-diethylethanmine were added dropwise 3.63 parts of ethyl chloroformate, keeping the temperature below 10° C. After stirring for 1/2 hour at 10° C., the whole was added to a solution of 6.26 parts of ethyl 4-amino-3-methoxy-1-piperidinecarboxylate in 145 parts of trichloromethane at 10° C. Stirring was continued for 1/2 hour at room temperature. The reaction mixture was washed with water, NaOH 5% and water and was then dried, filtered and evaporated. The residue was suspended in 2,2'-oxybispropane. The product was filtered off and dried, yielding 12.3 parts (93.2%) of ethyl cis-4-[(4-amino-5-chloro-2,3-dihydro-2,2-dimethyl-7-benzofuranyl)carbonylamino]-3-methoxy-1-piperidinecarboxylate (interm. 1).

Provenance & Evidence