Triethylamine → (+/-)-cis-1-(2-Azido-cyclohexyl)-4-(4-chlorobenzyl)-piperidine

Participants

Reaction Steps

A murky solution of (±)-trans-4-nitro-benzenesulfonic acid 2-azido-cyclohexyl ester (1.77 g, 5.41 mmol), 4-(4-chlorobenzyl)-piperidine (1.14 g, 5.43 mmol), and Et3N (0.75 mL, 5.4 mmol) in CH3CN (11.2 mL) was stirred at room temperature for 17 hours, 65° C. for 31 hours, and 80° C. for 5 d, allowed to cool to room temperature, and concentrated. The residue was partitioned between CH2Cl2 and 1 N NaOH, the aqueous phase was extracted with CH2Cl2 and the extracts were dried and concentrated. Chromatography of the residue with 98:1.9:0.1–95:4.75:0.25 CH2Cl2:MeOH:NH4OH to 100% MeOH and subsequent chromatography with 10:1 hexanes:EtOAc to 100% EtOAc followed by 95:5 EtOAc:MeOH gave, in order of elution, starting (±)-trans-4-nitro-benzenesulfonic acid 2-azidocyclohexyl ester (1.2 g, 68%), desired product (155 mg, 9%), and starting 4-(4-chlorobenzyl)-piperidine (810 mg, 71%). Product: 1H NMR δ 1.19–1.81 (m, 12H), 1.92–2.08 (m, 3H), 2.22 (m, 1H), 2.48 (d, J=7.0 Hz, 2H), 3.02 (m, 2H), 4.05 (m, 1H), 7.06 (m, 2H), 7.23 (m, 2H); MS m/z 333.2 (M+H)+.

Provenance & Evidence