Methyl Acrylate → 5-Methoxy-3-(2-methoxycarbonyl-vinyl)-indazole-1-carboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

A solution of 3-iodo-5-methoxy-indazole-1-carboxylic acid tert-butyl ester [0.500 g, Reference Example 22(a)] in dioxane (15 ml) and under an atmosphere of nitrogen was treated with triethylamine (1.86 ml) followed by methyl acrylate (1.20 ml), triphenylphosphine (0.105 g), and palladium (II) acetate (60 mg). The resulting mixture was heated at 50° C. for 16 hours, then cooled to ambient temperature and then evaporated. The residue was partitioned between ethyl acetate and water. The organic layer was washed with brine, then dried over magnesium sulfate and then evaporated. The residue was subjected to flash column chromatography on silica eluting with a mixture of ethyl acetate and 40/60 petrol (1:9, v/v) to yield 5-methoxy-3-(2-methoxycarbonyl-vinyl)-indazole-1-carboxylic acid tert-butyl ester (282 mg). LC-MS (METHOD B): RT=3.33 minutes; 333 (M+H)+.

Provenance & Evidence