Propionic Acid → 4-Chloro-6-methyl-10,10-dioxo-2-propionylamino-10,11-dihydro-5-oxa-10lambda*6*-thia-dibenzo[a,d]cycloheptene-8-carboxylic acid methyl ester

Participants

Reaction Steps

A solution of oxalyl chloride (0.17 mL, 2.03 mmol) and propionic acid (0.15 mL, 2.03 mmol) in dichloromethane (20 mL) was stirred for 1 h. Compound of Example 1 (0.5 g, 1.35 mmol) in DMF (5 mL) was added to the reaction mixture at 25° C. and stirred for 18 h. The solvent was removed under vacuum, water (25 mL) was added and the solid precipitated was filtered. The crude product was purified by column chromatography (silica gel, 1% methanol in chloroform) to obtain the title compound. Yield: 0.28 g, (60%); mp: 226-228° C.; 1H NMR (DMSO-d6, 300 MHz): δ 1.06 (t, 3H, CH3), 2.33 (q, 2H,CH2), 2.64 (s, 3H, CH3), 3.85 (s, 3H, OCH3), 5.30 (s, 2H, CH2), 7.66 (d, 1H, Ar), 7.88 (s, 1H, Ar), 8.10 (s, 1H, Ar), 8.15 (s, 1H, Ar), 10.26 (s, 1H, NH); MS: m/e (El) 423 (M+); analysis: C19H18ClNO6S requires C, 53.66,H, 4.28, N, 3.30, Cl, 8.32, S, 7.56; found: C, 53.38,H, 4.27, N, 3.48, Cl, 8.64, S, 7.75%.

Provenance & Evidence