Reaction of p-tolualdehyde hydrazone with disulfur dichloride in the presence of DBU gave 2,5-di (p-tolyl)-1,3,4-thiadiazole (1a) in 54% yield. Phenyldiazomethane also reacted with disulfur dichloride to afford 2,5-diphenyl-1,3,4-thiadiazole (1b) in 80% yield.
Efficient Synthesis of Conjugated 1,3,4-Thiadiazole Hybrids through Palladium-Catalyzed Cross-Coupling of 2,5-Bis(4-bromophenyl)-1,3,4-thiadiazole with Boronic Acids
New derivatives of 2,5-bis(4-heteroarylphenyl)-1,3,4-thiadiazole were synthesized under Suzuki cross-coupling reactions from 2,5-bis(4-bromophenyl)-1,3,4-thiadiazole and commercially available boronic acids. Reactions were conducted in a two-phase solvent system in the presence of catalytic amounts of tetrakis(triphenylphosphine)palladium(0), cesium carbonate as a base, and tetrabutylammonium bromide