Methyl phenothiazin-2-yl ether → Di-p-toluoyltartaric acid

Participants

Reaction Conditions

Reaction Steps

(±)-10-(3 Dimethy]amino-2-methylpropyl)-2-methoxyphenothiazine (16.5 g; 0.05 mole), (-)-di(p-toluoyl)-L-tartaric acid monohydrate (10.15 g; 0.025 mole) and ethanol (75 cc) are introduced into a 250-cc three-necked round-bottomed flask equipped with a mechanical stirrer, a condenser and a nitrogen inlet. The stirred mixture is heated to 60° C. until a homogeneous solution is obtained. The mixture is cooled to 50° C. and crystallization is then seeded by adding a few crystals of the neutral salt of (-)-di(p-toluoyl)tartaric acid and the dextrorotatory base. While stirring is maintained, the mixture is kept for 1 hour at 50° C., cooled to 20° C. in the course of 2 hours, and maintained at 20° C. for 1 hour. The crystals obtained are separated by filtration, washed with ethanol (2×30 cc) and then dried. The neutral salt (12.99 g) of (-)-di(p-toluoyl)tartaric acid and dextrorotatory 10-(3-dimethylamino-2-methylpropyl) -2-methoxyphenothiazine is thereby obtained.

Provenance & Evidence