Ammonia → 4-Chloro-6-methyl-10,10-dioxo-2-piperazin-1-yl-10,11-dihydro-5-oxa-10lambda*6*-thia-dibenzo[a,d]-cycloheptene-8-carboxylic acid methyl ester hydrochloride

Participants

Reaction Conditions

Reaction Steps

Aqueous ammonia solution (25%, 300 mL) was added to 2-[bis-(2-chloroethyl)-amino]-4-chloro-6-methyl-10,10-dioxo-10,11-dihydro-5-oxa-10lambda*6*-thia-dibenzo[a,d]-cycloheptene-8-carboxylic acid (52 g, 0.109 mol) [prepared by alkaline hydrolysis of compound of Example 12] in methanol (100 mL). The reaction mixture was sealed under nitrogen atmosphere, kept at 110° C. for 9 h, cooled and the seal was opened. The reaction mixture was concentrated to remove solvent and ammonia, and azeotroped with toluene. The product was taken in methanolic HCl solution (300 mL) and stirred at 70° C. for 9 h. The reaction mixture was cooled, solid separated was filtered, washed with methanol and dried under vacuum to obtain the crude product. The crude product was dissolved in chloroform and treated with aqueous sodium carbonate to obtain the free base, which was purified by column chromatography (silica gel, 5% methanol in chloroform) to obtain freebase of the title compound. Yield: 32 g (68%). This was converted to the hydrochloride salt using methanolic HCl. mp: 277-280° C.; 1H NMR (DMSO-d6, 300 MHz): δ 2.66 (s, 3H, CH3), 3.19 (m, 4H, 2CH2), 3.40 (m, 4H, 2CH2), 3.85 (s, 3H, OCH3), 5.10 (s, 2H, CH2), 7.10 (s, 1H, Ar), 7.20 (s, 1H, Ar), 8.05 (s, 1H, Ar) and 8.20 (s, 1H, Ar); MS: m/e (ES+) 437 (M+1, free base); analysis: C20H22Cl2N2O6S requires C, 50.75; H, 4.68; N, 5.92; Cl, 14.98; S, 6.77. found: C, 50.85; H, 4.62; N, 6.14; Cl, 15.30; S, 6.80%.

Provenance & Evidence