Pyridine → 2,8-Dimethyl-3H-quinazolin-4-one

Reaction equation

[NH2:1][C:2]1[C:10]([CH3:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([NH2:6])=[O:5].N1C=CC=[CH:14][CH:13]=1.C(Cl)(=O)C>C1COCC1>[CH3:13][C:14]1[NH:6][C:4](=[O:5])[C:3]2[C:2](=[C:10]([CH3:11])[CH:9]=[CH:8][CH:7]=2)[N:1]=1

Participants

Procedure

To a solution of 2-amino-3-methylbenzamide (0.5 g, 3.3 mmol) (prepared by conventional methods) and pyridine (0.35 ml, 4.3 mmol) in dry THF (15 ml), was added a solution of acetyl chloride (0.36 ml, 5.0 mmol) in THF (2 ml). dropwise, and the mixture was stirred overnight under nitrogen. The solvent was removed under vacuum and the remaining white slurry was resuspended in 2% aqueous sodium hydroxide solution and neutralised with aqueous hydrochloric acid, whereupon a white precipitate formed. The solid was collected and recrystallised from methanol-water to furnish the required quinazolinone (0.47 g, 81%) m.p. 217-220° C.;