Dimethylamine → Drometrizole

Participants

Reaction Steps

24.1 g (0.1 mol) of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole-N-oxide, 0.125 g of 5% palladium carbon, 150 ml of a solvent mixture comprising toluene and water (ratio by volume, 4:1) and 7 g of 50% dimethylamine were charged into a 500-ml four neck flask. After the air in the flask had been replaced by nitrogen, the resultant mixture was agitated at room temperature. Hydrogen was then supplemented to allow for the amount of hydrogen absorbed by the mixture, which was then subjected to reaction until no more hydrogen was absorbed by it. After the reaction had been completed, the catalyst was filtered off, and part of the filtrate was subjected to quantitative analysis using gas chromatography (GC). The results revealed a yield of 89% of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole. The solvent was then distilled off from the filtrate, and the residual solid was crystallized using ethanol and then washed with ethanol to obtain 18 g of 2-(2'-hydroxy-5'-methylphenyl) benzotriazole (yield, 80%; melting point, 128° to 130° C.).

Provenance & Evidence