Sulfuric Acid → 2-(2-hydroxy-5-t-butylphenyl)benzotriazole-N-oxide

Participants

Reaction Conditions

Reaction Steps

2-nitro-2'-hydroxy-5'-t-butylazobenzene 19.9 g was added to a mixture of secondary butanol 80 g, water 14 g and 97% sodium hydroxide 11.2 g, and the resultant mixture was stirred while raising temperature to 65° C. Thereafter, the mixture was cooled to 50° C., and 9-fluorenone 1.5 g was added to the mixture. The reaction mixture was then stirred at 90°~95° C. for five hours to effect reaction, thus almost all of the azobenzene having disappeared. Thereafter, water 50 ml was added to the reaction liquor, and the reaction liquor was neutralized to pH 8 with 62% sulfuric acid 15 g. The neutralized reaction liquor was then cooled to 20° C. or lower to precipitate a crystal. The crystal thus obtained was filtered to separate the crystal, and the separated crystal was then fully washed with water and further with a small amount of methanol. The washed crystal was then dried, thus producing 15.5 g of 2-(2-hydroxy-5-t-butylphenyl)benzotriazole-N-oxide having a melting point of 95° to 98° C. at the yield of 82.0%.

Provenance & Evidence