Phosphorus oxychloride → 1217472-10-0

Participants

Reaction Conditions

Reaction Steps

The solution of 7-methoxy-4-methyl-2H-phthalazin-1-one (3) in POCl3 (15 mL) is heated at reflux (120° C.) for 3 h 50 min and then cooled to room temperature. Unreacted POCl3 is removed at reduced pressure followed by azeotroping with toluene (2×10 mL). The residue is diluted with sat. NaHCO3 (60 mL) and extracted with dichloromethane (200 mL, 60 mL, and 50 mL). The extract is washed (brine) and dried. After solvent removal at reduced pressure, the residue is dried under high vacuum to give 2.08 g (100%) of 4 as a yellow solid, mp 151-153° C. IR 2968, 1613, 1218 cm−1; 1H NMR (CDCl3) δ 2.97 (s, 3H, CH3), 4.07 (s, 3H, CH3O), 7.50-7.59 (m, 2H, 6,8-PhthH), 8.01 ppm (d, J=8.7 Hz, 1H, 5-PhthH).

Provenance & Evidence