The preparation and reactivity of some potassium Purine-, Quinazoline-, and Tetrahydroquinazoline-sulphonates

Abstract

The potassium salts of purine-6(and 8)-, 9-methylpurine-6-, quinazoline-2(and 4)-, 5,6,7,8-tetrahydroquinazoline-4-, and 5,6,7,8- tetrahydro-2-methylquinazoline-4-sulphonic acid are prepared by treatment of the corresponding thiones with aqueous potassium permanganate. All the suphonates undergo ready hydrolysis to the corresponding oxo derivatives in acid and also in alkali (except for the first two purines which are stabilized as dianions therein) ; t_1/2 values at H₀ - 1 (25°) are all less than 8 min; at pH 14 (40°) they vary from 2 to 190 min. Potassium quinazoline-4-sulphonate undergoes hydrazinolysis to 4-hydrazinoquinazoline; quinazoline-2-sulphonyl fluoride (prepared by chlorine oxidation of quinazoline-2-thione in the presence of potassium hydrogen difluoride) reacts with appropriate amines to give 2-diethylamino-, 2-dipropylamino-, and 2-amino- quinazoline; and purine-6-sulphonyl fluoride with hydrazine gives purine-6-sulphonohydrazide or 6-hydrazinopurine, according to conditions.