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A straightforward, two-step synthesis of fluoro substituted chromeno[2,3- c ]pyrazol- and [1]benzothieno[2′,3′:5,6]pyrano[2,3- c ]pyrazol-4(1 H )-ones, respectively, is presented. Hence, treatment of 1-substituted or 1,3-disubstituted 2-pyrazolin-5-ones with fluoro substituted 2-fluorobenzoyl chlorides or 3-chloro-6-fluoro-1-benzothiophene-2-carbonyl chloride using calcium hydroxide in refluxing 1,4-dioxane gave the corresponding 4-aroylpyrazol-5-ols, which were cyclized into the fused ring systems. 5-Fluorochromeno[2,3- c ]pyrazol-4(1 H )-one was obtained upon treatment of the 1-(4-methoxybenzyl) protected congener with trifluoroacetic acid. Treatment of 5-fluorochromeno[2,3- c ]pyrazol-4(1 H )-ones with methylhydrazine afforded novel tetracyclic ring systems such as 2-methyl-7-phenyl-2,7-dihydropyrazolo[4′,3′:5,6]pyrano[4,3,2- cd ]indazole. Detailed NMR spectroscopic investigations ( 1 H, 13 C, 15 N, 19 F) with the obtained compounds were undertaken.

A straightforward two-step synthesis of title compounds (IV) and (IX) and their NMR data are given.

The title compound was prepared by treatment of 5-fluoro-1-phenylchromeno [2,3-c]pyrazol-4(1H)-one with aqueous dimethylamine. Detailed spectroscopic data (1H NMR, 13C NMR, 15N NMR, IR, MS) are presented.