Sodium Hydroxide → 5-Methyl-2,3-dihydro-1,4-benzodioxine-6-carboxylic acid

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Reaction Steps

In 5 ml of tetrahydrofuran was dissolved 0.8 g of 5-methyl-1,4-benzodioxan-6-carbaldehyde, then 27 ml of a 1% sodium hydroxide aqueous solution was added dropwise to the solution and further 0.5 g of a 10% palladium-carbon was added thereto, and the mixture was refluxed under heating for 1.5 days. The mixture was cooled to room temperature, 10 ml of a 10% sodium sulfite aqueous solution was added thereto and after stirring for 30 minutes, the mixture was filtered and the tetrahydrofuran was removed under reduced pressure. The residue was adjusted to pH 3 with a 5% hydrochloric acid and extracted with diethyl ether. The diethyl ether layer was washed successively with water and saturated saline solution and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure to obtain 0.53 g of the titled 5-methyl-1,4-benzodioxan-6-carboxylic acid (yield: 61%).

Provenance & Evidence