Sulfuric Acid → 2-(2'-Hydroxy-methylphenyl) benzotriazole

Beteiligte Stoffe

Reaktionsschritte

To the wet product 12 g (~ 0.4 mol) thus obtained, is added methanol (60 ml), water (30 ml), 97% sodium hydroxide (13.0 g) and 9-fluorenone (0.5 g), and glucose (5.5 g) (0.3 mol) is further added to the mixture over an hour while stirring at 50° to 55° C. The mixture is reacted while stirring at 75° C. (boiling point) for 5 hours. As a result, the N-oxide disappears. The reaction liquor is neutralized with 62% sulfuric acid (19.8 g) to pH 8 to precipitate a crystal. The precipitated crystal is separated by filtration, and the separated crystal is fully washed with water and further with methanol. The washed crystal is then dried, thus obtaining 9.4 g of 2-(2'-hydroxy-methylphenyl) benzotriazole having a melting point of 128 to 130° C. at the yield of 92.8%. One can see that the reduction with aromatic ketones takes over 9 hours to complete. This reduction also required the use of two catalysts and a greater amount of total catalysts.

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