Reduction of Amide to Primary Amine

Lithium aluminum hydride (244 mg, 6.44 mmol) was added to dry THF (50 ml) and the suspension was cooled to 0°C. A solution of amide 22a (450 mg, 1.0 mmol) in THF (15 ml) was added dropwise and the mixture was refluxed for 3 hr. The mixture was cooled in an ice bath and quenched with 10% NaOH and the resulting solids were filtered. The filtrate was dried (Na₂SO₄), filtered, and concentrated to yield amine 23a (235 mg, 98%) as an oil, which was used without further purification. ¹H NMR (400 MHz, CDCl₃) δ 1.51–1.62 (m, 4H), 1.70–1.81 (m, 1H), 2.92–3.11 (m, 4H), 2.72–2.86 (m, 9H), 3.22–3.30 (m, 1H), 3.37–3.50 (m, 2H), 3.55–3.58 (m, 1H), 3.77 (s, 3H), 7.24– 7.29 (m, 2H), 6.63–6.65 (m, 1H), 6.67–6.7 (m, 1H), 6.85–6.9 (m, 3H), 6.97–7.01 (d, 1H, J = 8 Hz).