Methane → 300843-20-3

Participants

Reaction Steps

Heating of a mixture of 1-(4-chloranilino)-4-(4-pyridylmethyl)-phthalazine (Example 4 in WO 98/35958) and charcoal in boiling methanol for about 7 days in an open vessel leads to partial oxidation of the methylen-bridge of 1-(4-chloranilino)-4-(4-pyridylmethyl)-phthalazine. After cooling to RT, unchanged 1-(4-chloranilino)-4-(4-pyridylmethyl)-phthalazine crystallizes out and can be filtered off. Chromatography (SiO2; dichloromethane/methanol 98:2) of the concentrated filtrate then leads to [4-(4-chloranilino)phthalazin-1-yl](pyridin-4-yl)ketone and rac. [4-(4-chloranilino)phthalazin-1-yl](pyridin-4-yl)methanol (see Expl. 78 in WO 98/35958). [4-(4-Chloranilino)phthalazin-1-yl](pyridin-4-yl)ketone: 1H NMR (DMSO-d6) δ9.88 (bs, 1H, HN), 8.79 (d, 2H, pyridine), 8.71 (d, 1H), 8.63 (d, 1H), 8.07 (m, 2H), 7.97 (d, 2H, chloranilino), 7.77 (d, 2H, pyridine), 7.45 (d, 2H, chloranilino); IR (KBr): 3287, 3139, 3066, 1667 (CO), 1620 cm−1; FAB MS (M+H)+=361. rac [4-(4-Chloranilino)phthalazin-1-yl](pyridin-4-yl)methanol: m.p. 197-197.5 dec; 1H NMR (DMSO-d6) δ9.32 (bs, 1H, HN), 8.57 (d, 1H), 8.49 (d, 2H, pyridine), 8.22 (d, 1 H), 8.00 (d, 2H, chloranilino), 7.93 (m, 1H), 7.84 (m, 1H), 7.41 (d, 2H, pyridine); 7.40 (d, 2H, chloranilino), 6.77 (d, 1H, HO), 6.30 (d, 1H, HC-OH); IR (KBr): 3386 (OH), 3122, 2852, 1619, 1600, 1521, 1493, 1406 cm−1; FAB MS (M+H)+=363.

Provenance & Evidence