Aluminum(III) Chloride → 1'-Benzyl-6-chloro-3,4-dihydrospiro[chromene-2,4'-piperidine]

Participants

Reaction Steps

To a stirred suspension of AlCl3 (3.04 g, 22.8 mmol) in dichloromethane (75 ml) tert-butylamine-borane (1:1) (3.98 g, 45.8 mmol) was added at 0° C., and the stirring was continued for 15 min at this temperature to obtain a clear solution. A solution of 1′-benzyl-6-chlorospiro[chromene-2,4′-piperidin]-4(3H)-one (2.61 g, 7.6 mmol) in dichloromethane (15 ml) was added dropwise. The stirring was continued for 2 h at 0° C. and for 3 h at room temperature. The reaction mixture was quenched by dropwise addition of 0.1 N aq. HCl. After the gas evolution has ceased, the layers were separated. The organic layer was washed with 0.1 N HCl (2×50 ml) and brine (50 ml), and dried over Na2SO4. The solvent was removed in vacuo to afford subtitle compound as colourless solid (1.63 g, 65%).

Provenance & Evidence