1-Benzyl-1H-pyrazole-4-carbonyl chloride synthesis

Yield:1174665-95-2 95%

Reaction Conditions:

with thionyl chloride in toluene at 20;Reflux;

Steps:

51

1-Benzyl-1H-pyrazole-4-carboxylic acid (1.6g, 7.92mmol) was stirred as a suspension in toluene (2OmL) at RT and thionyl chloride (1.88g, 1.15mL, 15.8mmol) was added. The reaction mixture was slowly heated to reflux and heating continued for 4hrs. After cooling the reaction was concentrated in vacuo. Toluene was added to the residue and concentrated in vacuo. This was repeated a further three times with toluene and twice with isohexane. The crude oil obtained was used without further purification, 1.65g, 95%.

References:

WO2009/93012,2009,A1 Location in patent:Page/Page column 78