Synthesis and evaluation of antimicrobial activity of 4H-pyrimido[2,1-b]benzothiazole, pyrazole and benzylidene derivatives of curcumin

► One-pot syntheses of novel curcumin derivatives have good biological activities. ► First example of three component reaction of curcumin using pyridine as catalyst. ► First time that we have isolated and characterized the reaction intermediates. ► Easy synthesis of pyrazoles and benzylidenes of curcumin which possesses good antimicrobial activity.