As a part of ongoing studies in developing new Tyrosinase inhibitors, a class of structurally novel 2-(2, 4-dimethoxy phenylamino)-5 methylene-4-thiazolinone derivatives were synthesized by incorporating 2-(2, 4-dimethoxy-phenylamino)-thiazol-4-one with various 1- (1-methyl-buta-1, 3-dienyl)-3-phenyl-1H-pyrazole-4-carbaldehyde. The results showed that some of the synthesized compounds exhibited significant inhibitory activities. Especially, 5 ...