Hydrazine hydrate (1:1) → HCID 135519368, compound

Participants

Reaction Conditions

Reaction Steps

6-Chloro-7-hydroxy-3-(4methoxy-phenyl)-4-oxo-4H-chromene-2-carboxylic acid (1 eq) was taken up in ethanol and hydrazine hydrate (3 eq) was added. To aid dissolution a few drops of NaHCO3 (aq) was added, and then all was heated at 70° C. under nitrogen for 2 hours. The solution was cooled to room temperature and concentrated in vacuo to a brown oil. This was partitioned between 1MHCl(aq) and diethyl ether. The organic phases were combined, washed with 1MHCl(aq), dried over MgSO4, filtered and concentrated in vacuo to give 5-(5-chloro-2,4dihydroxy-phenyl)-4-(4-methoxy-phenyl)-2H-pyrazole-3-carboxylic acid as a yellow foam.

Provenance & Evidence