Chloroform → 2-(2-Chloroethyl)-2,3-dihydro-4-methylpyrido[3,2-f][1,4]-thiazepin-5(4H)-one

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Reaction Steps

A mixture of 80.75 g (0.34 mole) of 2-[(1-methyl-3-pyrrolidinyl)thio]-3-pyridinecarboxylic acid, 500 ml of chloroform, 200 g of carbon tetrachloride and 178 g (0.68 mole) of triphenylphosphine was stirred at reflux for 2.5 hr. The resulting solution was extracted with one 500 ml and three 125 ml portions of 1N hydrochloric acid. The acid extracts were combined and extracted with isopropyl ether. The aqueous layer was basified with sodium hydroxide and extracted three times with chloroform. The combined chloroform extract was dried over sodium sulfate and concentrated. A portion of the residue was chromatographed on the high pressure liquid chromatograph using a silica column and ethyl acetate. The compound obtained was crystallized from isopropyl ether-isopropyl alcohol, m.p. 97°-100° C.

Provenance & Evidence