Methylamine → 6-Methoxy-N,2-dimethyl-1-benzothiophene-3-carboxamide

Participants

Reaction Steps

A solution of this crude 6-methoxy-2-methylbenzo[b]thiophene-3-carbonyl chloride in THF (50 ml) was combined with a 2.0 M solution of CH3NH2 in THF (20 ml, 40 mmole). The resultant reaction mixture was stirred at ambient temperature for 3 hours. The solvent was removed by concentration, in vacuo, and the residue obtained was partitioned between H2O (50 ml) and CH2Cl2 (50 ml). The layers were separated and the aqueous phase was extracted with CH2Cl2 (2×30 ml). The combined organic extracts were dried over Na2SO4 and concentrated, in vacuo, to give 0.8 g of an amber solid which was purified by silica gel chromatography. Elution with CH2Cl2: EtOAc (80:20) and evaporation of the appropriate fractions gave 693 mg (72%) of an off-white solid. 1H NMR (DMSO-d6) δ8.15 (1H, q, J=4.6 Hz), 7.62 (1H, d, J=8.9 Hz), 7.47 (1H, d, J=2.4 Hz), 6.97 (1H, dd, J=2.4, 8.9 Hz), 3.79 (3H, s, 2.80 (3H, d, J=4.6 Hz), 2.53 (3H, s). Anal. Calcd. for C12H13NO2S: C, 61.25; H, 5.57; N, 5.95; S, 13.63. Found: C, 60.97; H, 5.56; N, 5.85; S, 13.44.

Provenance & Evidence