Sodium Bicarbonate → 3-(2-ethoxyethyl)-N-[1-[2-(phenylsulfonyl)ethyl]-4-piperidinyl]-3H-imidazo-[4,5-b]pyridin-2-amine hemihydrate

Participants

Reaction Steps

A mixture of 3.7 parts of [(2-bromoethyl)sulfonyl]benzene, 4.34 parts of 3-(2-ethoxyethyl)-N-(4-piperidinyl)-3H-imidazo[4,5-b]pyridin-2-amine, 2.5 parts of sodium hydrogen carbonate and 120 parts of ethanol was stirred for 2 hours at reflux temperature. The reaction mixture was filtered over diatomaceous earth and the filtrate was evaporated. The residue was taken up in water and the product was extracted with 4-methyl-2-pentanone. The extract was dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (97:3 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from a mixture of tetrahydrofuran and 2,2'-oxybispropane. The product was filtered off and dried, yielding 2.6 parts (37.1%) of 3-(2-ethoxyethyl)-N-[1-[2-(phenylsulfonyl)ethyl]-4-piperidinyl]-3H-imidazo-[4,5-b]pyridin-2-amine hemihydrate; mp. 101.9° C. (compound 99).

Provenance & Evidence