1-[1-(4-Chlorophenyl)pyrazol-3-yl]oxypropan-2-one → methyl (Z,2E)-5-[1-(4-chlorophenyl)pyrazol-3-yl]oxy-2-methoxyimino-4-methylpent-3-enoate

Participants

Reaction Steps

To 5.26 g (21.0 mmol) 1-[1-(4-chlorophenyl)pyrazol-3-yl]oxypropan-2-one and 7.20 g (26.9 mmol) methyl (2Z)-3-diethoxyphosphoryl-2-methoxyimino-propanoate (which can be prepared as described for the dimethoxy derivative [(Tetrahedron Let 29, 3361-3364 (1988)] in 100 ml THF have been added at ambient temperature with stirring 2.59 g (23.1 mmol) potassium tert.-butylate. Stirring was continued over night. After removal of the solvent in vacuo the mixture was purified by chromatography on silica with heptane/ethyl acetate. 1.07 g of a 80:20 E:Z-mixture have been collected. This has been used directly for the next step.

Provenance & Evidence