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

Participants

Reaction Conditions

Reaction Steps

6-Chloro-7-hydroxy-3-(4-methoxy-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 1M HCl (aq) and diethyl ether. The organic phases were combined, washed with 1M HCl (aq), dried over MgSO4, filtered and concentrated in vacuo to give 5-(5-chloro-2,4-dihydroxy-phenyl)-4-(4-methoxy-phenyl)-2H-pyrazole-3-carboxylic acid as a yellow foam.

Provenance & Evidence