Dimethylformamide → Pirodavir

Participants

Reaction Conditions

Reaction Steps

A mixture of 10.4 parts of 3-chloro-6-methylpyridazine, 22.4 parts of ethyl 4-[2-(4-piperidinyl)ethoxy]benzoate butanedioate (1:1), 8.6 parts of sodium carbonate and 0.9 parts of N,N-dimethylformamide was stirred for 3 hours in an oil bath at ±150° C. After cooling, water and dichloromethane were added and the layers were separated. The organic layer was dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and ethanol (99:1 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from a mixture of 2,2'-oxybispropane and 2-propanone (75:25 by volume). The precipitated product was filtered off and dried, yielding 17 parts (56.8%) of ethyl 4-[2-[1-(6-methyl-3-pyridazinyl)-4-piperidinyl]ethoxy]benzoate; mp. 130.1° C. (comp. 1).

Provenance & Evidence