p-Toluenesulfonic acid → 4-Chloro-6-methyl-2-morpholin-4-yl-10,10-dioxo-10,11-dihydro-5-oxa-10lambda*6*-thia-dibenzo[a,d]cycloheptene-8-carboxylic acid methyl ester

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Reaction Steps

Catalytic amount of p-toluene sulphonic acid (PTSA) was added to a stirred solution of compound of Example 13 (1 g, 2.19 mmol) in xylene (50 mL). Reaction mixture was refluxed in Dean-Stark apparatus for 6 h and xylene was removed by distillation. Reaction mixture was diluted with 50 mL water, neutralized using 10% sodium bicarbonate solution and extracted using ethyl acetate (3×50 mL), washed with brine (2×10 mL), dried on sodium sulphate. The crude product obtained was purified by column chromatography (silica gel, ethylacetate/pet. ether) to obtain the title compound. Yield: 0.32 g, (33%); mp: >320° C.; 1H NMR (DMSO-d6, 300 MHz): δ 2.68 (s, 3H, CH3), 3.15 (s, 4H, 2CH2), 3.74 (s, 4H, 2CH2), 3.90 (s, 3H, OCH3), 4.65 (s, 2H, CH2), 6.76 (s, 1H, Ar), 6.88 (s, 1H, Ar), 8.06 (s, 1H, Ar), 8.44 (s, 1H, Ar); MS: m/e (EI) 437 (M+).

Provenance & Evidence