Dimethyl acetylenedicarboxylate → HCID 86690035, compound

Participants

Reaction Steps

To a solution of 3-(4-fluorobenzoyl)-2,3-dihydrobenzo[d]thiazole-2-carbonitrile (8.1 g, 28.0 mmol) in dichloromethane (50 mL) was added dropwise 8 mL of tetrafluoroboric acid (HBF4). The solution was stirred for 3 h at room temperature. The brown precipitates appeared were collected by filtration and the filter cake was washed with ether. The solid salt was added to a solution of dimethyl acetylenedicarboxylate (12.2 g, 84.0 mmol) in DMF (40 mL) and then warmed at 35° C. for 14 h. The reaction mixture was concentrated in vacuo and the residue was crystallized from methanol to give dimethyl 1-(4-fluorophenyl)benzo[d]pyrrolo[2,1-b]thiazole-2,3-dicarboxylate, 2.5 g (23%); mp 186-187° C. 1H NMR (DMSO-d6) δ 3.63 (3H, s, COOMe), 3.83 (3H, s, COOMe), 6.78-6.80 (1H, m, ArH), 7.28-7.30 (1H, m, ArH), 7.30-7.44 (3H, m, 3×ArH), 7.62-7.66 (2H, m, 2×ArH), 8.03-8.05 (1H, m, ArH). Anal. Calcd. for (C20H14FNO4S): C, 62.65; H, 3.68; N, 3.65; S, 8.36. Found: C, 62.68; H, 3.46; N, 3.62; S, 8.76.

Provenance & Evidence