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

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Reaction Steps

Methyl ester of Example 35j (0.5 g, 1.36 mmol) was added to solution of sodium methoxide [Na (0.156 g, 6.78 mmol) in methanol (6 mL)], which in turn was added to a solution of paraformaldehyde (0.057 g, 1.90 mmol) in MeOH (5 mL). The reaction mixture was stirred for 5 h at room temperature, treated with sodium borohydride (0.051 g, 1.36 mmol), refluxed for 1 h, cooled, treated with 1M aqueous KOH (1.5 mL) and stirred for 15 mins. It was extracted with ethyl acetate and the aqueous portion was neutralized to pH 5 with 10% aqueous HCl to obtain the title compound (J. Chem. Soc. Chem. Commun., 1334, (1984)). Yield: 38.46%; 1H NMR (DMSO-d6): δ 2.60 (s, 3H, N—CH3), 2.70 (s, 3H, CH3), 5.10 (s, 2H, CH2), 6.30 (d, 1H, NH), 6.65 (d, 1H, Ar), 7.50 (d, 1H, Ar), 8.08 (s, 1H, Ar), 8.20 (s, 1H, Ar); MS: m/e (EI+) 367 (M+).

Provenance & Evidence