p-Toluenesulfonic acid → HCID 15655149, compound

Participants

Reaction Steps

4-Methoxy-3-oxobutyric acid methyl ester (1.50 g, 10.3 mmol) was mixed with dimethylformamide dimethylacetal (1.83 g, 15.4 mmol) and a catalytic amount of para-toluene sulfonic acid and heated in the microwave for 15 min at 130° C. The mixture was cooled to room temp. and then concentrated in vacuo to afford a red oil. In a second flask para-chlorophenylhydrazine hydrochloride (1.84 g, 10.3 mmol) was placed in acetonitrile (10 mL) and then treated with the above red oil in triethylamine (6 mL). The mixture was stirred for 14 h, concentrated in vacuo and purified by silica chromatography (5% ethylacetate in hexanes) to afford 1-(4-Chloro-phenyl)-5-methoxymethyl-1H-pyrazole-4-carboxylic acid methyl ester (1.90 g, 66%).

Provenance & Evidence