Dimethyl acetylenedicarboxylate → HCID 86690038, compound

Participants

Reaction Steps

To a solution of 3-(4-methoxybenzoyl)-2,3-dihydrobenzo[d]thiazole-2-carbonitrile (5.3 g, 17.9 mmol) in dichloromethane (50 mL) was added dropwise 5 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 (7.6 g, 54.0 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-methoxyphenyl)benzo[d]pyrrolo[2,1-b]thiazole-2,3-dicarboxylate 1.7 g (24%); mp 167-168° C. 1H NMR (DMSO-d6) δ 3.63 (3H, s, COOMe), 3.82 (3H, s, COOMe), 3.86 (3H, s, Me), 6.84-6.86 (1H, m, ArH), 7.12 (2H, d, J=8.4 Hz, 2×ArH), 7.28-7.32 (1H, m, ArH), 7.37-7.40 (1H, m, ArH), 7.48 (2H, d, J=8.4 Hz, 2×ArH), 8.03-8.05 (1H, m, ArH). Anal. Calcd. for (C21H17NO5S): C, 63.79; H, 4.33; N, 3.54; S, 8.11.

Provenance & Evidence