Palmitoyl chloride → 7-chloro-4-(4-chlorophenyl)-2-[(1-oxohexadecyloxy)methyl]-5H-pyrido[3,4-b][1,4]benzothiazin-3(2H)-one

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Reaction Steps

To 1.0 g. of 7-chloro-4-(4-chlorophenyl)-2-(hydroxymethyl)-5H-pyrido[3,4-b][1,4]benzothiazin-3(2H)-one (2.6 mmol.) in 15 ml. of pyridine at 0° C. was added dropwise 0.9 ml. of hexadecanoyl chloride (3.9 mmol.). After stirring for 35 minutes, the mixture was poured onto ice-water and allowed to stand for 16 hours at room temperature, resulting in the formation of a yellow precipitate. The precipitate was collected, washed with water and air-dried, then purified using flash chromatography on silica gel, employing a mixture of 2% ethyl acetate: 98% methylene chloride as the eluent. Fractions containing the product were combined and triturated with ether to yield 7-chloro-4-(4-chlorophenyl)-2-[(1-oxohexadecyloxy)methyl]-5H-pyrido[3,4-b][1,4]benzothiazin-3(2H)-one as a pale yellow crystalline solid (1.25 g; 78% yield) having the structural formula, ##STR21## a melting point in the range of 120°-122° C. and the following elemental analysis:

Provenance & Evidence