Cl.C[O:3][C:4]([C:6]1[S:10][C:9]2[CH:11]=[CH:12][CH:13]=[CH:14][C:8]=2[C:7]=1[NH:15][CH2:16][CH2:17][NH2:18])=O.C[O-].[Na+].Cl>CO>[NH:15]1[C:7]2[C:8]3[CH:14]=[CH:13][CH:12]=[CH:11][C:9]=3[S:10][C:6]=2[C:4](=[O:3])[NH:18][CH2:17][CH2:16]1A solution of 3-(2-aminoethylamino)benzo[b]thiophene-2-carboxylic acid methyl ester hydrochloride (339 mg, 1.18 mmol) and freshly prepared sodium methoxide (from 134 mg, 2.48 mmol of sodium) in 5 mL of methanol is heated at reflux for 18 hours. Upon cooling, the reaction is neutralized with 25 mL of 1N HCl and cooled to 0° C. for 1 hour. The resulting yellow crystalline material is filtered and dried under vacuum at 60° C. for several hours to provide 2,3-dihydro-1H-benzothieno [3,2-e]-1,4-diazepin-5-one in 64% yield. Chromatography, eluting with a gradient of 2% methanol in ethyl acetate in 5% methanol in ethyl acetate, gives analytically pure, 2,3-dihydro-1H-benzothieno-[3,2-e]-1,4-diazepin-5-one, mp 210°-212° C.
Loading…
