Sulfamic acid catalyzed one-pot, three-component green approach: synthesis and cytotoxic evaluation of pyrazolyl-thiazole congenersElectronic supplementary information (ESI) available: Crystallographic data, the general synthetic procedure and 1H and 13C spectra of all synthesized compounds. CCDC 1524476. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7nj00042a

An efficient, operationally simple and one-pot multi-component approach has been developed for the construction of pyrazolyl-thiazoles using sulfamic acid (H 2 NSO 3 H) as a green catalyst in water. The notable features of this protocol include mild reaction conditions, enhanced selectivity with good yields and wide substrate scope, which makes it an attractive and useful process for the synthesis of biologically important newer pyrazolyl-thiazole compounds. A series of compounds ( 4a-z ) were synthesized and also evaluated for their cytotoxic activity against three human cancer cell lines. Among them, 4b , 4c and 4e exhibited considerable cytotoxicity with an IC 50 value of < 5 μM. A one-pot multi-component protocol has been developed for the synthesis of biologically important pyrazolyl-thiazoles using sulfamic acid as a green catalyst in water.