Acetic Anhydride → 4-methoxymethylene-6-bromo-4H-isoquinoline-1,3-dione

Participants

Reaction Conditions

Reaction Steps

6-Bromo-4H-isoquinoline-1,3-dione (120 mg, 0.500 mmol) and trimethyl orthoformate (106 mg, 1.00 mmol) were suspended in 1.25 ml of a 1:4 ratio mixture of acetic anhydride and N,N-dimethylformamide. Mixture is heated at 125° C. for 2 hours causing a yellow solid to form. Mixture is cooled to room temperature and filtered. Residue is washed with 20 ml of ethyl ether to afford the product as a yellow solid (109 mg, 0.380 mmol, 77%); 1H NMR (DMSO-d6) δ 4.25 (s, 3H), 7.60 (dd, J=1.9, 8.4 Hz, 1H), 7.96 (d, J=8.5 Hz, 1H), 8.07 (s, 1H), 8.36 (d, J=1.9 Hz, 1H), 11.38 (s, 1H); mass spectrum [(+) ESI], m/z 282/284 (M+H)+.

Provenance & Evidence