Multicomponent reaction protocol has been developed for the synthesis of novel pyrimidine fused pyrazolo [3,4-b]pyridine derivatives (7 a-g) and hexahydroquinazoline fused pyrazolo [3,4-b] pyridine derivatives (8 a-i) starting from 3-amino-5carbethoxy-6-trifluoromethyl pyrazolo[3,4-b] pyridine 5. All the synthesized compounds were evaluated for antibacterial as well as antifungal activities and compounds 7 f, 8 a, 8 c and 8 d exhibited promising antibacterial activity. In particular, compound 2,4,6-trifluoro substituted pyrimidine fused pyrazolo [3,4-b]pyridine (7 f) showed very good antibacterial activity against the panel of both Gram-positive and -negative bacterial strains. Hexahydroquinazoline fused pyrazolo [3,4-b]pyridine derivatives (8 f-i) also showed promising antifungal activity and broadspectrum anti-biofilm activity against both Gram-positive and negative bacterial strains. The crystal structure of compound 8 b was solved based on single crystal X-ray diffraction study. Docking studies were performed to identify the interactions of the compounds 7 f with crtM enzyme of Staphylococcus aureus.

An efficient chemoselective synthesis of 1,3‐thiazine‐2‐ylidenes was achieved via annulations of β‐aroyl‐thioacetamide with propargyl alcohols using BF3 OEt2 as Lewis acid catalyst. A broad spectrum of substrates was well tolerated under the mild reaction conditions producing desired thiazine heterocyclics in good yields.

Azabicyclo[3.1.0]amine analogues of anacardic acid (16a, 16b, 18a, 18b, 19 and 19b) were synthesized from anacardic acid and tested for their antibacterial activity against Gram positive and Gram negative bacteria. Most of the compounds are having potency at par with ampicillin and inferior with other standard drugs.

We have successfully accomplished gem‐difluorination of triazole alkyl functionalized amino pyrazoles in the presence of Selectfluor under dry condition and obtained 4,4‐difluoro pyrazol‐3‐imines derivatives in high yield. However, in the presence of water, 4,4‐difluoro pyrazol‐3‐one derivatives were afforded.

An efficient method for the synthesis of α‐fluoroamides having C–F quaternary stereogenic center was achieved by a one‐pot four‐component strategy under mild reaction conditions. A variety of α‐fluoroamides was synthesized by using 1,3‐dicarbonyl, isocyanide, acetylenedicarboxylate and N‐fluorobenzenesulfonimide (NFSI) systems with good to excellent yields up to 93 %. The current protocol proceeds through the unstable 3‐fluoro 4H‐pyran intermediate, which is key for the reaction and further it can be hydrolyzed due to the high electronegativity of the fluorine atom to produce the desired α‐fluoroamides.