Phosphoric Acid → 1-(4-Chloro-phenyl)-7-hydroxy-6-methoxy-1,4-dihydro-2H-isoquinolin-3-one

Participants

Reaction Conditions

Reaction Steps

To a suspension of 4-hydroxy-3-methoxyphenylacetonitrile (150 g, 0.919 mol) in phosphoric acid 85% (877 mL, 15.000 mol) was added 4-chlorobenzaldehyde (168 g, 1.195 mol), then the reaction mixture was heated at 120° C. for 2 h. After cooling to 90° C., the reaction mixture was slowly poured into the stirred 4 L of iced water. Resulting suspension was stirred at RT for 2 h, then filtered and washed with 500 mL of water 4 times. Crude and wet material was stirred in acetonitrile (1 L) at RT for 1 h, then filtration and dry up gave the title intermediate (163.6 g, 0.539 mol, 58.6%). HPLC: EtRet=4.20 min; LC-MS: m/z 304.0 [M+H]+; 1H NMR (400 MHz, DMSO-d6) 3.25-3.53 (m, 2H), 3.72 (s, 3H), 5.47 (d, J=3.12 Hz, 1H), 6.53 (s, 1H), 6.72 (s, 1H), 7.24 (d, 2H), 7.37 (d, 2H), 8.42 (d, J=3.51 Hz, 1H), 8.86 (br. s., 1H).

Provenance & Evidence