Sodium Bicarbonate → (1,1'-Biphenyl)-3-carboxylic acid

Participants

Reaction Steps

3′-Amino-2′-hydroxy-5′-methyl-biphenyl-3-carboxylic acid hydrochloride 11f (360 mg, 1.11 mmol) was dissolved in 3.7 mL of hydrochloric acid (1 N) upon cooling by an ice-water bath, followed by dropwise addition of 1.5 mL of aqueous sodium nitrite (85 mg, 1.22 mmol). After the mixture was stirred for 20 minutes, 5-methyl-2-(3-methyl-indan-5-yl)-2,4-dihydro-pyrazol-3-one 38f (228 mg, 1.0 mmol) was added. The mixture was adjusted to pH 8 with saturated aqueous sodium bicarbonate, followed by addition of 2 mL ethanol. The reaction mixture was warmed up to room temperature and reacted overnight. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was filtered and the filter cake was dissolved in 30 mL of water. After mixing well, the mixture was adjusted to pH 3˜4 with concentrated hydrochloric acid. The mixture was filtered and the filter cake was dried followed by addition of 10 mL dichloromethane. The mixture was stirred for 1 hour and filtered. The filter cake was dried to obtain the title compound 2′-hydroxy-5′-methyl-3′-{N′-[3-methyl-1-methyl-indan-5-yl)-5-oxo-1,5-dihydro-pyrazol-4-ylidene]-hydrazino}-biphenyl-3-carboxylic acid 39 (240 mg, yield 49.8%) as a red solid.

Provenance & Evidence