FOUR-COMPONENT SYNTHESIS OF FUNCTIONALIZED 1, 3, 4-OXADIAZOLE DERIVATIVES BEARING THE 2-AMINOBENZOTHIAZOLE MOIETY

A one-pot eighteen derivatives of N-((5-(aryl)-4H-pyrazol-3-yl)(aryl)methyl)benzo[d]thiazol-2-amine (5a-r) were synthesized from 2-aminobenzothiazole, aromatic aldehyde, N-isocyaniminotriphenylphosphorane on reaction with aryl carboxylic acid derivatives under a catalyst-free condition in CH2Cl2 by a Ugi-4CR/aza-Wittig cyclization at room temperature in fairly good yields (except for 5r, in which the aldehyde used has an electron-donating group). The newly synthesized compounds were confirmed and deduced based on IR, H-1 NMR, C-13 NMR, and mass spectroscopy, and elemental analysis.