Dimethylamine → Rocastine fumarate

Participants

Reaction Conditions

Reaction Steps

To a solution of 113 ml (1.0 mole) of 40% aqueous dimethylamine and 326 ml of ethanol in a steel bomb was added 48.4 g (0.189 mole) of 2-(2-chloroethyl)-2,3-dihydro-4-methylpyrido[3,2-f][1,4]-oxazepine-5(4H)-thione. The mixture was heated at 100° C. for 14 hr. The ethanol was removed in a rotary evaporator leaving some water in the residue. The residue was dissolved in 200 ml of methylene chloride and washed with three 100 ml portions of 20% aqueous potassium carbonate solution. The combined aqueous layers were extracted with three 150 ml portions of methylene chloride. Methylene chloride solutions were combined and treated with charcoal. Charcoal was filtered off and the filtrate was evaporated to give an oil. The oil was dissolved in 215 ml isopropyl alcohol and the solution was heated to a slow boil. A solution of 21.9 g (0.19 mole) of fumaric acid in 150 ml of boiling methanol was added to the isopropyl alcohol solution. Crystalline solid was obtained weighing 63.4 g (88%). The solid was recrystallized from hot 200 proof ethyl alcohol. The crystals were filtered off and triturated in isopropyl ether at room temperature and again separated by filtering. After drying in a vacuum oven overnight at 85° C., crystals in the amount of 72.45 g (79%), m.p. 130°-133° C., were obtained.

Provenance & Evidence