N-methyl-2-pyrrolidone → 7,8-Dichloro-1H-1,2,4-thiadiazolo[3,4-b]quinazolin-5-one-2,2-dioxide

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Reaction Steps

To a stirred slurry of 4,5-dichloroisatoic anhydride (11.54 g, 50 mmol) in N-methyl-2-pyrrolidinone (50 ml) under nitrogen is added sodium hydride (2.05 g of 60% oil dispersion, 52 mmol). The mixture is stirred for 30 min at room temperature, and to the resulting solution is added S-methyl-N-(chloromethanesulfonyl)-isothiourea (11.0 g, 55 mmol). The mixture is stirred under nitrogen at 80° C. for 18 hr, then worked up as in Example 4 above. Recrystallization from DMF provides the title compound as a white solid, mp >300° C. (4.69 g, 31%).

Provenance & Evidence