Methanesulfonic Acid → Isopropanol

Participants

Reaction Conditions

Reaction Steps

In 37.8 kg of 88% formic acid was dissolved 7.5 kg (91% pure, 36.37 mole) of 1-(4-pyridyl)-1,3-diketo-2-oximinopentane and 7.0 kg of methanesulfonic acid. The resulting solution was slowly added to a slurry of 8.3 kg of zinc powder in 35.7 kg of formic acid. The reaction temperature was kept at about 60° C. by proper cooling and slow addition. The mixture was allowed to stir at 55° C. for 2 hours and then cooled to 20° C. The solid zinc formate was filtered off. To the formic acid filtrate was added 3.6 kg of methanesulfonic acid. The formic acid was removed at the reduced pressure (40 mm Hg) and 70° C. To the residue was added a solution of 5.9 kg of methanol and 53.3 kg of isopropanol and stirred at 20° C. for 4 hours. Solid material was collected by centrifugation, washed with 12.5 kg of 10% methanol in isopropanol giving 11.0 kg, 87% yield, of the title compound as dimethanesulfonate salt after drying.

Provenance & Evidence