1-Chloroethyl chloroformate → 4-(1-Benzofuran-2-yl)-1,2,3,6-tetrahydropyridine

Participants

Reaction Steps

To a solution of the foregoing tetrahydropyridine (1.1 g, 3.8 mmol) in dichloromethane (50 ml) at 0° C. was added 1-chloroethylchloroformate (493 μl, 4.6 mmol), keeping the temperature below 0° C. The reaction was allowed to warm to room temperature over 1 hr, after which the solvent was evaporated. Methanol (50 ml) was added to the residue and the mixture heated under reflux for 2 hrs. The solvent was removed by evaporation, and the residue chromatographed on silica, eluting with dichloromethane/methanol/ammonia (90:10:1), to yield the title compound as a buff solid (600 mg, 79%); δH (CDCl3) 2.44-2.48 (2H, m, tetrahydropyridinyl CH2), 3.14 (2H, t, J 5.8 Hz, tetrahydropyridinyl CH2), 3.60-3.63 (2H, m, tetrahydropyridinyl CH2), 6.54-6.58 (2H, m, CH=CR, 3'-H), 7.16-7.26 (2H, m, 5'-H, 6'-H), 7.42 (1H, d, J 7.8 Hz, 7'-H), and 7.50 (1H, d, J 7.2 Hz, 4'-H).

Provenance & Evidence