As a part of our continuing search for potential aniplatelet agent, 1-Benzyl-3-(5-hydroxymethyl -2-furyl)-5-phenylpyrazole (7b) was chosen as the lead compund.
The starting material was methyl 2-furoate(1), which was introduced by hydrogen chloride and paraformadehyde to prepare methyl 5-chloromethyl-2-furoate (2). The compound 2 was successively reacted with hexamethelentetramine, then hydrolysis the formed salt, and methyl 5-formyl-2-furomate (3) was yield.
Compound 4 was obtained from compound 3, which reacted with acetophenone in alkaline. And then compound 4 was proceeded cyclization with hydrazine hydrate to yield 3(or 5)-(5-ethoxy carbonyl-2-furyl)-5(or 3)-phenylpyrazole (5). Compound 5 was reacted successively with various kind of benzyl chlordie, and a series of 1-substituted benzyl-3(or 5)-(5-ethoxycarbonyl -2-furyl)-5(or 3)-phenylpyrazoles (6) was prepared. The reduction of compound 6 eventually brings the target compound.
We also completed the identification of positional isomers by exploiting the 1D and 2D NMR spectra. The inhibition of some tumor cell of tested compound was not significant, and activities of antiplatelet were still in progress.
