Hydrochloric Acid → HCID 21249378, compound

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Reaction Steps

2-Cyanoacetamide (1.85 g) is treated with 50% sodium hydride (1.28 g) in dimethylformamide (35 ml) under stirring at room temperature until the effervescence subsides. To this solution 1,4-dihydro-1-phenyl-[1]-benzothiopyrano[4,3-c]pyrazole-3-carbonyl chloride (6.53 g), prepared according to Example 15, dissolved in dioxane (35 ml) is added under stirring at room temperature. The reaction mixture is allowed to react for 2 hours, then is diluted with ice water and acidified to pH 1 with 37% HCl. The gummy precipitate is extracted with ethyl acetate and the organic solution washed with N HCl and then evaporated to dryness in vacuo. The residue is purified over SiO2 column, using chloroform/methanol 80:20 as eluent, to give 2-cyano-3-(1,4-dihydro-1-phenyl-[1]-benzothiopyrano[4,3-c]pyrazol-3-yl)-3-oxo-propanamide, m.p. >300° C. dec., NMR (DMSO d6) δ ppm: 4.10 (s) (2H, --S--CH2 --), 6.00-7.00 (bs) (2H, CONH2), 6.60-7.80 (m) (9H, phenyl protons), 9.00 (bs) (1H, OH).

Provenance & Evidence