1-Piperazinecarboxylic acid, ethyl ester → Ethyl 4-(6-chloropyridazin-3-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 7.5 parts of 3,6-dichloropyridazine in 75 parts of N,N-dimethylformamide was added dropwise a solution of 8 parts of ethyl 1-piperazinecarboxylate and 5.6 parts of N,N-diethylethanamine in 25 parts of N,N-dimethylformamide. Upon completion, the whole was stirred overnight at a temperature of about 50° C. After cooling, the reaction mixture was poured onto water and the product was extracted with trichloromethane. The organic layer was dried, filtered and evaporated. The residue was crystallized from 2-propanol, yielding 3.6 parts of ethyl 4-(6-chloro-3-pyridazinyl)-1-piperazinecarboxylate; mp. 123.8° C. (compound 208).

Provenance & Evidence