Sulfuric Acid → Drometrizole

HRID 257656

반응식

HRID 257656 반응식
[OH-].[Na+].O=C[C@@H]([C@H]([C@@H]([C@@H](CO)O)O)O)O.[OH:15][C:16]1[CH:21]=[CH:20][C:19]([CH3:22])=[CH:18][C:17]=1[N:23]1[N+:27]([O-])=[C:26]2[CH:29]=[CH:30][CH:31]=[CH:32][C:25]2=[N:24]1.S(=O)(=O)(O)O>C1C2C(=O)C3C(=CC=CC=3)C=2C=CC=1.O.CO>[OH:15][C:16]1[CH:21]=[CH:20][C:19]([CH3:22])=[CH:18][C:17]=1[N:23]1[N:27]=[C:26]2[CH:29]=[CH:30][CH:31]=[CH:32][C:25]2=[N:24]1

참가 물질

8

반응물 4

HCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 107526(2R,3S,4R,5R)-2,3,4,5,6-pentahydroxyhexanalHCID 132146462-(2-hydroxy-5-methylphenyl)benztriazole N-oxide

생성물 1

HCID 17113Drometrizole수율 92.8%

시약·촉매·용매 3

HCID 10241Fluorenone촉매HCID 887Methanol용매HCID 962Water용매

실험 절차

Example 5 of U.S. Pat. No. 4,835,284 is duplicated. Water (70 ml), 97% sodium hydroxide 5.2 g, 2-nitro-2'-hydroxy-5'-methylazobenzene (12.9 g) and toluene (10 ml) are mixed and heated to 60° C. After stirring, hydroquinone (0.6 g) is added and glucose (5.0 g) is added to the mixture over one hour at 40° to 45° C. The mixture is further stirred for two hours, and the azobenzene disappears. The reaction liquor is neutralized with 62% sulfuric acid 5.8 g, and is cooled to 20° C. to precipitate a crystal. The crystal thus precipitated is separated by filtration to obtain a wet product 12 g of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole-N-oxide (dry weight: 10.8 g, yield 90.0%, and melting point: 138° C. to 140° C.). To the wet product (12 g) thus obtained, are added methanol (60 ml), water (30 ml), 97% sodium hydroxide (13.0 g) and 9-fluorenone (0.5 g), and glucose (5.5 g) is further added to the mixture over one 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-5'-methylphenyl)benzotriazole having a melting point of 128° to 130° C. at the yield of 92.8%. One can see that the reaction using an aromatic ketone takes over 9 hours to complete. Two catalysts are also required.

후처리

  1. additionis further added to the mixture over one hour
  2. customThe mixture is reacted
  3. stirringwhile stirring at 75° C. (boiling point) for 5 hours
  4. customto precipitate a crystal
  5. customThe precipitated crystal is separated by filtration
  6. washthe separated crystal is fully washed with water and further with methanol
  7. customThe washed crystal is then dried

출처 및 근거

ORD 기록
ord-fcda0faead224a2096c76369bb9b90e0
출처 데이터셋
uspto-grants-1993_11
특허 번호
US05262541

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