1-(3-Methyl-4-methylenepyrazolo [5, 1-c][1, 2, 4] triazin-6 (4H-yl) ethanone 9a and its 7- methyl-9b and 7-phenyl-derivative 9c undergo Heck coupling to afford (Z)-1-{4-benzylidene- 3-methylpyrazolo [5, 1-c][1, 2, 4] triazin-6 (4H)-yl} ethanones 10a–c and substituted benzylidene analogues 10d–m as the major geometrical isomers in low yields. The most potent agent in a human tumour screen in vitro was 10b (mean GI50 value 4.9 μM in a ...