Synthesis and antibacterial activity of some novel thiourea, naphtho[2,3-d]thiazole, quinazoline and thieno[2,3-d]pyrimidine derivatives containing sulfonamido moieties

p-Substituted sulfamoylphenyl isothiocyanates 1a-d were prepared using reported procedures. The reactivity of 1a-d towards some nitrogen nucleophiles was investigated. Thus, interaction of 1 with aromatic amines and anthranilic acids furnished N-1,N-3-disubstituted thioureas 2a-c and 3-[4-N-substituted sulphonamido]phenyl-2-thioxo-4-(3H)-quinazolin-4-ones 4a-f, respectively. Alkylation of 4c with ethyl chloroacetate in acetone containing anhydrous potassium carbonate to yield quinazoline 5. Hydrazinolysis of 5 using ethanolic hydrazine hydrate afforded the corresponding acid hydrazide 6. Finally, treatment of 1a,b,d with 2-amina-3-cyano-4,5,6,7-tetrahydrobenzor[b]thiophene yielded thieno[2,3-d]pyrimidines 10a-c bearing sulphonamido moieties. Structures of the new compounds were established by their elemental analyses and pectral data. Also, the most of these compounds were tested in vitro for their antimicrobial activity against some Gram positive and Gram negative bacteria.