Methanol → Drometrizole

Participants

Reaction Steps

To the wet product 12 g thus obtained, were added methanol 60 ml, water 30 ml, 97% sodium hydroxide 13.0 g and 9-fluorene 0.5 g, and glucose 5.5 g was further added to the mixture over one hour while stirring at 50° to 55° C. The mixture was reacted while stirring at 75° C. (boiling point) for 5 hours. As this result, the N-oxide disappeared, thus Process (c) being completed. The reaction liquor was neutralized with 62% sulfuric acid 19.8 g to pH 8 to precipitate a crystal. The precipitated crystal was separated by filtration, and the separated crystal was fully washed with water and further with methanol. The washed crystal was then dried, thus obtaining 9.4 g of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole having a melting point of 128° to 130° C. at the yield of 92.8%.

Provenance & Evidence