3,4,5,6-Tetrahydrophthalic anhydride → HCID 22924027, compound

Participants

Reaction Steps

To a stirred suspension of 3,4,5,6-tetrahydrophthalic anhydride (0.38 grams, 2.5 mmol) and methyl 3-amino-3-(3,4-dimethoxyphenyl)propionate hydrochloride (0.69 grams, 2.5 mmol) in acetic acid (10 mL) was added sodium acetate (0.21 grams, 2.5 mmol). The suspension was refluxed under nitrogen overnight. The acetic acid was removed in vacuo to afford an orange oil which was taken up in water (5 mL) and the pH was adjusted to 7 using a saturated solution of sodium bicarbonate. The resulting mixture was extracted with methylene chloride (3×20 mL). The combined organic extracts were dried over magnesium sulfate, filtered and concentrated in vacuo to afford 0.62 grams of crude product as a yellow oil. The crude product was purified by flash chromatography (silica gel, 35% ethyl acetate/hexane) and the resulting solid was dried in vacuo (60° C., <1 mm) to afford 0.22 g (23%) of product as a pale yellow solid: 1H NMR (CDCl3) δ 7.09-6.99(m, 2H), 6.84-6.75(m, 1H), 5.60-5.48(m, 1H), 3.87(s, 3H), 3.85(s, 3H), 3.71-3.55(m, 1H), 3.65(s, 3H), 3.23-3.06(m, 1H), 2.38-2.21(m,4H), 1.85-1.64(m, 4H); 13C NMR (CDCl3) δ 171.1, 170.8, 148.9, 148.7, 120.1, 111.2, 110.9, 55.9, 55.8, 50.4, 36.1, 21.2, 19.9. Anal. Calcd for C20H23NO6. Theoretical: C, 64.33; H, 6.21; N, 3.75. Found: C, 64.25; H, 6.10; N, 3.70.

Provenance & Evidence