Acetic Anhydride → HCID 75968173, compound

Participants

Reaction Steps

Compound 18 was synthesized by two methods. In the first method, acetic anhydride (3 ml) was added drop-wise to an ice-cold solution of compound 1 (300 mg, 0.96 mmol) in formic acid (6 ml), and the reaction mixture was stirred at room temperature for 16 h. The solvent was distilled-off under vacuum. The solid obtained was recrystallized from chloroform and hexanes to obtain 18 as a yellow solid (148 mg, 45% yield). In the second method, ammonium formate (121 mg, 1.92 mmol) was added to a solution of compound 1 (300 mg, 0.96 mmol) in dry acetonitrile. The mixture was refluxed for 24 h, before evaporating to dryness. The solid was recrystallized from methylene chloride and hexanes to obtain pure 18 as a yellow solid (190 mg, 57% yield). Rf (60:40 ethyl acetate:hexanes)=0.60. 1H NMR (400 MHz, CDCl3): δ 8.16 (s, 1H, CHO), 8.09, 8.06 (2s, 2H, C═CH), 7.60-7.22 (m, 8H, Ar—H), 4.87, 4.66 (2s, 4H). 13C NMR (100 MHz, CDCl3): δ 185.34, 162.14 (d, J=45.6), 160.95, 159.87 (d, J=45.9), 132.85, 132.19 (d, J=25.7), 131.12 (d, J=25.4), 130.78, 124.46 (d, J=3.1), 116.49 (d, J=22.1), 116.18 (d, J=22.3), 46.38 (d, J=5.4), 41.11 (d, J=5.2). ESI Mass calculated for C20H15F2NNaO2 (M+Na)+362.10. found 362.07.

Provenance & Evidence