反应详情

Using an analogous procedure to that described in the first paragraph of the portion of Example 1 which is concerned with the preparation of starting materials, 4-carboxyanthranilic acid (14.2 g) was reacted with formamide to give 7-carboxyquinazolin-4-one (8.5 g). A mixture of a portion (4 g) of the material so obtained, methanol (40 ml) and concentrated sulphuric acid (2 ml) was stirred and heated to reflux for 6 hours. The mixture was cooled to ambient temperature and the precipitate was isolated. There was thus obtained 7-methoxycarbonylquinazolin-4-one (5.7 g).