Sulfuric Acid → Tinuvin

Participants

Reaction Steps

In order to conduct the reaction of Process (c), the system was heated, and was stirred at 66° to 68° C. (boiling point) for 5 hours. As this result, the N-oxide disappeared, thus Process (c) being completed. Thereafter, water 50 ml was added to the reaction liquor, and the resultant reaction liquor was neutralized with 62% sulfuric acid 10 g to precipitate a crystal. The precipitated crystal was separated by filtration, and the separated crystal was fully washed with hot water of 60° to 70° C. and further with a small amount of methanol. The washed crystal was then dried, thus obtaining 8.7 g of 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole having a melting point of 138° to 140° C. at the yield of 82.9%.

Provenance & Evidence