The condensation between 2-fluorobenzylhydrazine (I) and the sodium enolate of ethyl cyanopyruvate (II) in the presence of trifluoroacetic acid produced the pyrazole derivative (III). Subsequent cyclization of aminopyrazole (III) with (dimethylamino)acrolein (IV) gave the pyrazolopyridine (V). Amonolysis of the ethyl ester group of (V) afforded amide (VI), which was further dehydrated to nitrile (VII) by means of trifluoroacetic anhydride and pyridine. Addition of sodium methoxide to nitrile (VII) furnished imidate (VIII). This was converted to the corresponding amidine (IX) upon treatment with ammonium chloride and HOAc. Finally, the title diamino pyrimidine compound was obtained by heating a mixture of amidine (IX) and morpholinomalononitrile (X).
The reaction of 2-cyclopropylacetonitrile (I) with ethyl formate (II) by means of t-BuOK in THF gives the hydroxymethylene derivative (III), which is cyclized with 1-(2-fluorobenzyl)pyrazolo[3,4-b]pyridine-3-carboxamidine (IV)(see scheme no. 28591301a, intermediate (IX)) by heating at 105 C to afford the target aminopyrimidine derivative.