Sulfuric Acid → 8-Chloroisoquinolin-3-ol

Participants

Reaction Conditions

Reaction Steps

Concentrated sulfuric acid (18 M; 7.0 mL) was added to N-(2-chlorobenzyl)-2,2-dimethoxyacetamide (2.21 g, 9.07 mmol) at ambient temperature, and the solution was stirred overnight at ambient temperature and at 60° C. for 5 h. The cooled reaction mixture was added to ≈50 mL of ice, and the pH of the yellow mixture was adjusted to 7 with NaHCO3 solution. The yellow precipitate was filtered off, washed with water, and dried in vacuo, giving the title compound as yellow solid. The material was used in the next step without further purification. 1H NMR (400 MHz, DMSO-d6): δ=11.13 (brs, 1H), 9.11 (s, 1H), 7.72 (d, J=8.4 Hz, 1H), 7.54 (dd, J=8.2, 7.2 Hz, 1H), 7.45 (dd, J=0.8, 7.2 Hz, 1H), 7.00 (s, 1H). MS(ES+): m/z=180.07/182.02 (100/38) [MH+]. HPLC: tR=2.45 min (polar—5 min, ZQ3).

Provenance & Evidence