Sodium Hydroxide → 4,5,6,7-Tetrahydro-1H-indazole-3-carboxylic acid

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Reaction Steps

A solution of 4,5,6,7-tetrahydro-1H-indazole-3-carboxylic acid ethyl ester [0.606 g, Reference Example 18(a)] in methanol (50 ml) was treated with sodium hydroxide (0.500 g). The mixture was refluxed for 16 hours, then cooled and then evaporated. The residual white solid was treated with hydrochloric acid (30 ml, 2N) and the resulting solution was extracted three times with ethyl acetate (50 ml). The combined organic extracts were dried over sodium sulfate and then evaporated to yield 4,5,6,7-tetrahydro-1H-indazole-3-carboxylic acid (0.424 g) as a white solid. LC-MS (METHOD B): RT=2.44 minutes; 167 (M+H)+. (b) 5-Isopropyl-1H-pyrazole-3-carboxylic acid

Provenance & Evidence