Phosphorus oxychloride → 4-Chloro-6,7-dimethoxyquinazoline

Participants

Reaction Conditions

Reaction Steps

Sulfolane (250 ml) and phosphorus oxychloride (250 ml=412.5 g, 2.69 mol) were added to 6,7-dimethoxy-4-quinazolone (50.1 g, 0.24 mol), and the mixture was stirred at 120° C. for one hr. The reaction mixture was cooled to room temperature, and the excess phosphorus oxychloride was then removed by distillation under the reduced pressure. The residue was poured into ice water (1000 ml), and chloroform (1000 ml) was added thereto. The aqueous layer was adjusted to pH 6.5 by the addition of a 20% sodium hydroxide solution, followed by the separation of the organic layer from the aqueous layer. The separated organic layer was washed with water (1000 ml×six times), was dried over sodium sulfate, and was then concentrated under the reduced pressure. Tetrahydrofuran (470 ml) was added to the residue, and the mixture was refluxed. The reaction solution was cooled to −5° C. to −10° C. and was filtered and dried to give 38.5 g (yield 71.4%) of the target product.

Provenance & Evidence