4-tert-Butylcyclohexylamine → HCID 178497211, compound

Participants

Reaction Steps

A mixture of methyl 4-oxochromane-7-carboxylate (2.06 g, 9.99 mmol), titanium (IV) isopropoxide (3.27 mL, 10.99 mmol), 4-tert-butylcyclohexyl amine (3.10 g, 19.98 mmol) in absolute ethanol (40 mL) was stirred under nitrogen at room temperature for 17 h. Sodium borohydride (0.45 g, 11.99 mmol) was then added and the resulting mixture was stirred for an additional 3 h at room temperature. The reaction was quenched by pouring into aqueous ammonia (2N, 100 mL). The resulting inorganic precipitate was filtered off through Celite and washed with CH2Cl2 (200 mL). The organic layer was separated and the remaining aqueous layer was extracted once with CH2Cl2 (100 mL). The combined organic extracts were dried over Na2SO4, filtered and concentrated. Chromatography (15% EtOAc in Hexane) afforded methyl 4-[(trans-4-tert-butylcyclohexyl)amino]chromane-7-carboxylate and the corresponding cis product (less polar). HPLC/MS: m/z=346.3 (M+1), Rt=1.95 min. 1H NMR (CDCl3): δ 7.57 (1H, dd, J=2.0 Hz, 8.0 Hz), 7.50 (1H, d, J=2.0 Hz), 7.35 (1H, d, J=8.0 Hz), 4.36 (1H, dt, J=2.5 Hz, 11.0 Hz), 4.27 (11H, dt, J=4.0 Hz, 11.0 Hz), 3.97 (1H, t, J=4.0 Hz), 3.93 (3H, s), 2.64-2.58 (1H, m), 2.18-2.15 (1H, m), 2.11-2.04 (1H, m), 1.97-1.91 (2H, m), 1.91-1.84 (2H, m), 1.22-1.02 (5H, m), 0.92 (9H, s).

Provenance & Evidence