Phosphorus oxychloride → 1-Chloro-6-methoxy-4-methylphthalazine
반응식
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[C:9](=O)[NH:8][N:7]=[C:6]2[CH3:14].O=P(Cl)(Cl)[Cl:17]>>[Cl:17][C:9]1[C:10]2[C:5](=[CH:4][C:3]([O:2][CH3:1])=[CH:12][CH:11]=2)[C:6]([CH3:14])=[N:7][N:8]=1참가 물질
3
반응 조건
- 온도
- 120 °C
실험 절차
A solution of 6-methoxy-4-methyl-2H-phthalazin-1-one (6) (2.0 g, 10.5 mmol) in POCl3 (20 mL) is heated at reflux (120° C.) for 4 h 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 (75 mL) and extracted with dichloromethane (150 mL, 2×60 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 2.2 g (100%) of 7 as a yellow solid, mp 123-126° C. IR 2991, 1611, 1403, 1290, 1234 cm−1; 1H NMR (CDCl3) δ 2.95 (s, 3H, CH3), 4.05 (s, 3H, CH3O), 7.25 (d, J=1.2 Hz, 1H, 5-PhthH), 7.55 (dd, J=6.0, 1.2 Hz, 1H, 7-PhthH), 8.21 ppm (d, J=6.0 Hz, 1H, 8-PhthH).