Water → HCID 14502136, compound

Participants

Reaction Steps

(-)-2-(2-cyano-10-phenothiazinyl)-1-propyl 1-phenyl-(S)-ethylammonium phthalate (95.4 g) is added to a solution of 23.5 g of potassium hydroxide in 1150 cc ethanol under reflux and reflux is continued while stirring for 10 minutes. The reaction mixture is then poured into iced water (1 liter) and extracted with ethyl acetate (2 liters and then 500 cc). The combined organic phases are washed successively with a 0.1N aqueous solution of hydrochloric acid (2×500 cc), with a saturated aqueous solution of sodium bicarbonate (2×500 cc) and with a saturated aqueous solution of sodium chloride (500 cc), dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (30 mm Hg; 4 kPa) at 40° C. The residual yellow solid (44 g) is taken up in isopropyl ether (200 cc) under reflux and the product crystallizes whilst warm. The mixture is allowed to return to a temperature of about 20° C. and the solid is centrifuged, washed with isopropyl ether (20 cc) and dried under reduced pressure (5 mm Hg; 0.7 kPa) at 20° C. D series 10-(1-hydroxy-2-propyl)-2-phenothiazinecarbonitrile (36.5 g) is thus obtained in the form of yellow crystals which melt at 135° C.

Provenance & Evidence