Folate antagonists. 22. Antimalarial and antibacterial effects of 2,4-diamino-6-quinazolinesulfonamides.

The synthesis and antimalarial activity of a series of 2,4-diamino-6-quinazolinesulfonamides (III) is described. Chlorosulfonation of 2,4-quinazolinediamine affords the 6-sulfonyl chloride, which upon treatment with the appropriate amine produces the desired products. Alternatively the sulfonyl chloride could be introduced by diazotization of the corresponding amine followed by treatment with SO2 in the presence of CuCl2.

Folate antagonists. 12. Antimalarial and antibacterial effects of 2,4-diamino-6-[(aralkyl and alicyclid)thio-, sulfinyl-, and sulfonyl]quinazolines.

A series of 2,4-diamino-6-[(aralkyl and alicyclic)thio-, sulfinyl-, and sulfonyl]quinazolines was prepared via condensation of 5-chloro-2-nitrobenzonitrile or 5,6-dichloro-2-nitrobenzonitrile with the appropriate aralkyl or alicyclic thiopseudourea, reduction of the resulting 2-nitro-5-[(aralkyl or alicyclic)thio]benzonitrile with stannous chloride to the amine, and cyclization with chloroformamidine hydrochloride. Oxidation was effected with hydrogen peroxide or the bromine complex of 1,4-diazabicyclo[2.2.