Hydroxyamine hydrochloride → 3-Cyanophenylboronic acid

Participants

Reaction Steps

In a three-necked flask with a capacity 3 liters, 123.4 g of the 3-formylphenylboronic acid prepared in Production Example 2, 68.6 g of hydroxylamine hydrochloride, 1050 ml of formic acid and 112.1 g of sodium formate are placed and mixed with each other. The resultant mixture liquid was heated for 8 hours while refluxing. The resultant reaction mixture liquid was left to stand in the ambient atmosphere for one night. Thereafter, in the case where a precipitate was generated in the reaction mixture liquid, this mixture liquid was agitated while cooling with ice and, in the case where no precipitate was generated in the reaction mixture liquid, the mixture liquid was mixed with a small amount of precipitation seed particles and agitated. From the resultant reaction mixture liquid, the solid precipitate was collected, by filtration and dried. The target compound, 3-cyanophenylboronic acid was obtained in an amount of 82.0 g. The yield thereof was 68%. The results of the 1H-NMR measurement of the target compound (200 MHz, δ ppm, CDCl3) were shown below.

Provenance & Evidence