Synthesis of 1,3-dibenzoyl- and 3-benzoyl-6-bromoquinazoline-2,4(1h,3h)-dione

The reaction of the 1,3-dibenzoyl derivative of 6-bromoquinazoline-2,4(1H,3H)-dione with potassium carbonate in anhydrous DMF at room temperature is accompanied by the evolution of carbon dioxide to form a highly soluble potassium salt of 3-benzoyl-6-bromoquinazoline-2,4(1H,3H)-dione and a slightly soluble potassium benzoate. In contrast to the dibenzoyl derivative of 6-methyluracil, N1-debenzoylation of the 1,3-dibenzoyl derivative of 6-bromoquinazoline-2,4(1 H,3H)-dion under the indicated conditions proceeds less selectively and partly gives the product of complete debenzoylation, 6-bromoquinazoline-2,4(1H,3H)-dione.