反应详情

Ethylamine (70% in water, 0.526 mL), followed by oxalaldehyde (40% in water, 0.889 mL) and ammonium acetate (473 mg) were added to a stirred solution of N-cyclohexyl-N-(2,2-dimethoxyethyl)-3-(3-formylphenethoxy)propanamide [Example 10, Step ii)] (400 mg) in methanol (3 mL). The mixture was stirred for 36 h. DCM was added and the mixture was washed with water. The volatiles were removed under vacuum and the crude product was purified by flash silica chromatography, elution gradient 50%-100% ethyl acetate in isohexane to afford the subtitled compound (98 mg). 1H NMR (400 MHz, CD3OD) δ 7.42-7.31 (m, 4H), 7.22 (d, J=1.5 Hz, 1H), 7.02 (d, J=1.3 Hz, 1H), 4.54 and 4.39 (2×t, J=5.5 Hz, 1H), 4.06-3.98 and 3.70-3.62 (2×m, 1H), 4.06 (q, J=7.3 Hz, 2H), 3.74-3.63 (m, 4H), 3.39-3.25 (m, 2H), 3.36 (s, 3H), 3.34 (s, 3H), 2.93-2.88 (m, 2H), 2.69-2.61 (m, 2H), 1.82-1.02 (m, 10H), 1.34 (t, J=6.8 Hz, 3H); a ˜1:1 mixture of rotamers is observed.

1. washthe mixture was washed with water
2. customThe volatiles were removed under vacuum
3. customthe crude product was purified by flash silica chromatography, elution gradient 50%-100% ethyl acetate in isohexane