3-Nitrophthalic anhydride → 3-(3-Nitrophthalimido)-3-(3-ethoxy-4-methoxyphenyl)propanenitrile

Participants

Reaction Steps

A stirred suspension of 3-nitrophthalic anhydride (0.24 g, 1.13 mmol) and 3-amino-3-(3-ethoxy-4-methoxyphenyl)propanenitrile (0.25 g, 1.13 mmol) in 6 mL of acetic acid was heated to reflux under nitrogen for 12 hours. The acetic acid was removed in vacuo to afford an orange gum which was dissolved in methylene chloride (10 mL) and was washed with a saturated aqueous solution of sodium bicarbonate (2×10 mL). The organic layer was separated and the aqueous layer was extracted with methylene chloride (10 mL). The combined organic extracts were dried over magnesium sulfate, filtered and concentrated in vacuo to afford a yellow oil. The crude product was purified by flash column chromatography (silica gel, 5% ethyl acetate/methylene chloride) and the resulting solid was dried in vacuio (60° C., <1 mm) to afford 0.25 g (56%) of 3-(3-nitrophthalimido)-3-(3-ethoxy-4-methoxyphenyl)propanenitrile as a yellow solid: mp 155.5-157° C.; 1H NMR (CDCl3) δ8.20-8.09 (m, 2H), 8.02-7.86 (m, 1H), 7.15-7.02 (m, 2H), 6.88-6.76 (m, 1H), 5.64 (dd, J=6.3, 10.6 Hz, 1H), 4.09 (q, J=7 Hz, 2H), 3.85 (s, 3H), 3.84 (dd, J=10.6, 16.7 Hz, 1H), 3.26 (dd, J=6.3, 16.7 Hz, 1H), 1.46 (t, J=7 Hz, 3H); 13C NMR (CDCl3) δ165.3, 162.3, 150.1, 148.7, 144.9, 135.7, 133.5, 129.0, 128.1, 127.4, 123.2, 120.3, 116.6, 112.1, 111.5, 64.6, 55.9, 51.9, 20.9, 14.7; Anal. calcd for C20H17N3O6. Theoretical: C, 60.76; H, 4.33; N, 10.63. Found: C, 60.59; H, 4.22; N, 10.65.

Provenance & Evidence