2-Methylsulfonyl-10-(3-chloropropyl)phenothiazine was prepared by
condensation of 1-bromo-3-chloropropane and 2-methylsulfonyl phenothiazine
in liquid ammonia in presence of obtained in situ sodium amide.
10 g 2-methylsulfonyl-10-(3-chloropropyl)-phenothiazine, 4 g piperidine-4-
carboxylic acid amide, 3.5 g dry sodium carbonate in 200 ml of ethanol was
heated to reflux for 24 hours. Than 1.75 g sodium carbonate was added and
the mixture was heated another 8 hours. After that the new 1.75 g portion of
sodium carbonate was added and heated for 16 hours. The solvent was
removed in vacuum (20 mm Hg). The residue was stirred with 50 ml water
and 150 ml ethyl acetate. The organic layer was separated and extracted with
200 ml 1 N hydrochloric acid. The water layer was made alkaline with 4 N
sodium hydroxide, extracted with ethyl acetate and dried over sodium sulfate.
The solvent was removed in vacuum (20 mm Hg) to dryness. The obtained
residue 2-methylsulfonyl-10-(3-(4-carbamoylpiperidino)propyl)phenothiazine
was recrystallized from ethyl acetate. Yield 6 g; MP: 170°-171°C.
