反应详情

温度

20 °C

Example 1 from EP 0,257,151 is duplicated. 2-nitro-2'-hydroxy-3', 5'-di-t-amylazobenzene (12.8 g) is added to a mixture of methanol (41 g), water (10 g) and 97% sodium hydroxide (11 g), and the resultant mixture is stirred at 65° C. for 30 minutes. Thereafter, 9-fluorenone (2.0 g) and then glucose (12 g) are added to the mixture at 60° to 65° C. over 4 hours. The resultant mixture is further stirred for 4 hours at the boiling point (70° C.), thus completing the reduction reaction. Thereafter, water (50 ml) is added to the reaction liquor, and the reaction liquor is neutralized with 62% sulfuric acid (13 g). The liquor thus neutralized is cooled to 20° C. to precipitate a crystal. The crystal thus obtained is separated by filtration, and the separated crystal is fully washed with water and further with methanol. The washed crystal is then dried, thus producing 9.9 g of 2-(2'-hydroxy-3', 5'-di-t-amylphenyl)benzotriazole having a melting point of 77° to 79° C. at the yield of 85.0%. One can see that the reduction reaction with the aromatic ketone 9-fluorenone takes over 81/2 hours to complete and requires three times as much catalyst.

1. customthe reduction reaction
2. customto precipitate a crystal
3. customThe crystal thus obtained
4. customis separated by filtration
5. washthe separated crystal is fully washed with water and further with methanol
6. customThe washed crystal is then dried