Hydrochloric Acid → 4-Chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid methoxy-methyl-amide

A suspension of 4-chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid (880 mg, 4.5 mmol) and N,O-dimethylhydroxylamine hydrochloride (459 mg, 4.7 mmol) in dichloromethane (30 ml) was treated at room temperature with N-methylmorpholine (476 mg, 4.7 mmol). Thereafter, in three portions 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (901 mg, 4.7 mmol) was added. The solution was stirred at room temperature overnight. For the workup, the reaction mixture was treated dropwise with hydrochloric acid (1M, 30 ml) and stirred for 10 minutes. The organic layer was separated, washed with water, then dried over sodium sulphate and evaporated. The crude material was purified by chromatography on silica gel using a 2:1-mixture of cyclohexane and ethyl acetate as the eluent. The 4-chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid methoxy-methyl-amide was obtained as a colourless oil (930 mg, 87%).

1. stirringstirred for 10 minutes
2. customThe organic layer was separated
3. washwashed with water
4. dry with materialdried over sodium sulphate
5. customevaporated
6. customThe crude material was purified by chromatography on silica gel using a 2

ORD record

ord-77900c535a6346aeb887326f9cdabe35

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09242943B2