Phosphorus oxychloride → 5-Chloro-1-methyl-1H-pyrazole-4-carboxylic acid

HRID 1031334

반응식

HRID 1031334 반응식
O[C:2]1[N:6]([CH3:7])[N:5]=[CH:4][C:3]=1[C:8]([O:10]CC)=[O:9].P(Cl)(Cl)([Cl:15])=O>>[Cl:15][C:2]1[N:6]([CH3:7])[N:5]=[CH:4][C:3]=1[C:8]([OH:10])=[O:9]

참가 물질

3

반응물 2

HCID 24813Phosphorus oxychlorideHCID 178469993HCID 178469993, 화합물

생성물 1

HCID 27357745-Chloro-1-methyl-1H-pyrazole-4-carboxylic acid

실험 절차

A mixture of 10 g of ethyl 5-hydroxy-1-methyl-4-pyrazole carboxylate and 50 ml of phosphorus oxychloride was stirred at 90° to 100° C. for 65 hours. Excessive phosphorus oxychloride was evaporated under reduced pressure, and the residue was poured into ice-water. The precipitated crystals were filtered and dried to obtain 4.5 g of 5-chloro-1-methyl-4-pyrazole carboxylic acid. The filtrate was neutralized with aqueous ammonia (28%) and extracted with ether. After drying of the extract, evaporation of the solvent gave 4.0 g of ethyl 5-chloro-1-methyl-4-pyrazole carboxylate. To 5-chloro-1-methyl-4-pyrazole carboxylic acid were added 30 ml of thionyl chloride and 0.2 ml of dimethylformamide, and the mixture was refluxed for 5 hours. Then, excessive thionyl chloride was evaporated and the residue was added to dry ethanol. After stirring at room temperature for 3 hours, the solvent was evaporated and ether was added to the residue. After washing with water, drying and evaporation of the solvent, there was obtained 4.5 g of ethyl 5-chloro-1-methyl-4-pyrazole carboxylate as an oil. Total of the title compound: 8.5 g.

후처리

  1. customExcessive phosphorus oxychloride was evaporated under reduced pressure
  2. additionthe residue was poured into ice-water
  3. filtrationThe precipitated crystals were filtered
  4. customdried

출처 및 근거

ORD 기록
ord-9f316e29fc1747239d33b37b83354cf7
출처 데이터셋
uspto-grants-1990_09
특허 번호
US04954164

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