Dimethylformamide → 4-Chloro-6-methoxyquinazolin-7-ol

Participants

Reaction Steps

Dimethylformamide (0.5 ml) was added to a solution of 7-(acetoxy)-6-methoxyquinazolin-4-(3H)-one (2.0 g, 8.5 mmol) in thionyl chloride (32 ml) and the reaction mixture was heated at reflux for 1.5 hours. Upon cooling to ambient temperature, the thionyl chloride was removed in vacuo and azeotroped twice with toluene. The residue was diluted with dichloromethane (15 ml), a solution of 10% ammonia in methanol (80 ml) added and the mixture heated at 80° C. for 10 minutes. Upon cooling to ambient temperature, the solvent was evaporated to almost complete dryness, water was added and the pH adjusted to 7 with dilute hydrochloric acid. The resultant precipitate was collected by filtration and dried in vacuo at 35° C. for 18 hours to yield 4-chloro-7-hydroxy-6-methoxyquinazoline (1.65 g, 92% yield):

Provenance & Evidence