The spiro analogues of benzothiazolylchromenopyranopyridine, benzothiazolyl- chromenoquinoline, benzothiazolylpyranoquinoline,
benzothiazolylchromenopyridopyrimidine and benzothiazolylpyranopyridopyrimidine have been
synthesized by an efficient domino reaction using sulfamic acid as catalyst in aqueous medium and screened for their cytotoxic
activity against tumor cell lines, namely human cancer cell lines of colon (sw620), breast (MCF-7), cervix (HeLa)
and heptatoma (HepG2) using a sulforhodamine B (SRB) assay. The synthesized compounds have shown promising cytotoxic
activity against MCF-7 (breast cancer) & HeLa (cervical cancer) cancer cell lines.