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nes. -17 Title compounds of type (V) are prepared and most of them show moderate to good antimycobacterial activity. Compound (Ve) exhibits maximum potency and is more active than the standard drug pyrimethamine. The X-ray structure of (Vb) is given. -(PONNUCHAMY, S.; KANCHITHALAIVAN, S.; RANJITH KUMAR*, R.; ASHRAF ALI, M.; SOO CHOON, T.; Bioorg. Med. Chem. Lett. 24 (2014) 4, 1089-1093, http://dx.doi.org/10.1016/j.bmcl.2014.01.007 ; Dep. Org. Chem., Madurai Kamaraj Univ., Madurai 625 021,Tamil Nadu, India; Eng.) -M. Bohle 31-134

An efficient one-pot four-component domino protocol for the combinatorial synthesis of novel 1,4-dihydropyrano[2,3-c]pyrazol-6-amines has been achieved. This transformation presumably occurs via cyclization-Knoevenagel condensation-Michael addition-tautomerism-intramolecular O-cyclization-elimination sequence of reactions. The significant features of this reaction include expedient one-pot process, short reaction time, no column chromatographic purification, excellent yield, and readily available starting materials.

The present investigation reports an easy access to a library of novel spiro-oxindole-pyrrolizine or pyrrolo[1,2-c]thiazole fused coumarin hybrid heterocycles through a one-pot sequential four-component reactions of 2,2-dimethyl-1,3-dioxane-4,6-dione, salicylaldehydes, isatins, and cyclic α-amino acids under ultrasound irradiation.