The cyclization of 5-amino-4-(4-methoxy-2-methylphenyl)-3-methylpyrazole with ethyl acetoacetate (II) in refluxing acetic acid gives 7-hydroxy-3-(4-methoxy-2-methylphenyl)-5-methylpyrazolo[1,5-a]pyrimidine (III), which is treated with POCl3 and diethylaniline in refluxing toluene yielding the corresponding chloro derivative (IV). Finally, this compound is treated with pentyl-3-amine in DMSO at 150 C.

Claisen condensation of 2,4-dichlorophenylacetonitrile (I) with ethyl acetate using of Na metal gave ketonitrile (II), which was reacted with hydrazine hydrate in the presence of AcOH to afford aminopyrazole (III). Subsequent condensation of (III) with ethyl acetimidate (IV) produced amidine (V). This was cyclized with diethyl carbonate and NaOEt to furnish the pyrazolotriazinone (VI). Chlorination of (VI) using phosphoryl chloride in N,N-dimethylaniline provided chloride (VII), which was finally coupled with 1,3-dimethoxy-2-aminopropane (VIII) to yield the title compound.