The ethyl 2-(4-chloro-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-2-yl)acetate (7.0 g, 0.0225 mol) and N-methyl cyclopropyl amine (4.8 g, 0.0675 mol) was dissolved in methanol (200 ml). To this reaction mixture, triethyl amine (13.66 g, 0.135 mol) was added slowly at room temperature. The resulting reaction mixture was stirred at room temperature for 18 h. After completion of reaction it was concentrated under reduced pressure. The residue was dissolved in DCM (250 ml) and it was washed with water. Aqueous layer was extracted with DCM (250 ml). Organic extracts were combined and washed with brine. Separated organic layer was dried over anhydrous Na2SO4 and concentrated to get crude compound. It was purified by column chromatography by using 100-200 mesh silica gel and 10% EtOAc:hexane as eluent to give ethyl 2-(4-(cyclopropyl(methyl)amino)-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-2-yl)acetate as a yellow solid. Yield—(6 g, 77.12%); 1H-NMR: (400 MHz, CDCl3); δ=4.20-4.10 (q, 2H), 3.88 (s, 2H), 3.1 (s, 3H), 2.90-2.86 (m, 3H), 2.84-2.83 (m, 2H), 1.93-1.87 (m, 2H), 1.77-1.71 (m, 2H), 1.41 (s, 1H), 1.26-1.23 (t, 3H), 0.72-0.68 (m, 2H), 0.45-0.41 (m, 2H); LC-MS [M+H]=345.9.
