Reaktion #2348919

Reaktionsgleichung

3-acetyl-2-methoxyimino-5-methyl-hexanoic acid ethyl ester

2,6-dichlorophenylhydrazine hydrochloride

→

title product

2-(2,6-Dichloro-phenyl)-4-isobutyl-5-methyl-2H-pyrazole-3-carboxylic Acid Ethyl Ester

Lösungsmittel

acetic acid

2-methoxy-ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe reaction is concentrated
2. 2
   Sonstigethe residue is partitioned between EtOAc and 1N HCl
3. 3
   EinengenThe organic layer is concentrated
4. 4
   Sonstigepurified by column chromatography (0-20% EtOAc in hexanes)

Vorschrift

A mixture of 3-acetyl-2-methoxyimino-5-methyl-hexanoic acid ethyl ester (1 g, 4.1 mmol), 2,6-dichlorophenylhydrazine hydrochloride (1.76 g, 8.2 mmol) in glacial acetic acid (10 mL) and 2-methoxy-ethanol (5 mL) is stirred at 105° C. for 3 hours. The reaction is concentrated and the residue is partitioned between EtOAc and 1N HCl. The organic layer is concentrated and purified by column chromatography (0-20% EtOAc in hexanes) to give the title product as an oil, 1.1 g (76%).

Quelle