Triethylamine → HCID 21833725, compound

Participants

Reaction Steps

A stirred solution of 2,3-dihydro-1'-methylspiro[4H-benzopyran-4,4'-piperidine] (D3, 1.0 g, 0.0046 mole) and diisopropylethylamine (1.2 ml, 0.0070 mole) in dichloroethane (20 ml) was treated with 1-chloroethyl chloroformate (0.64 ml, 0.0060 mole) and kept at room temp. for 1 h followed by 20 mins at reflux. The solution was then concentrated in vacuo and the residue treated with methanol (20 ml) and heated under reflux for 2 h. The reaction mixture was concentrated in vacuo to leave a beige solid, which was dissolved in dichloromethane (50 ml) and THF (10 ml) and treated with triethylamine (0.84 ml, 0.0060 mole) followed by ethyl chloroformate (0.44 ml, 0.0046 mole). The solution was stirred at room temperature for 2 h, then treated with 10% Na2CO3 solution (20 ml) and extracted with dichloromethane (2×40 ml). The combined extract was dried (Na2SO4) and concentrated in vacuo. The residue was chromatographed on silica gel eluting with 1:1 ether/60-80 petrol to afford the title compound as a yellow oil (1.3 g, 100%).

Provenance & Evidence