Sulfuric Acid → UV-328

HRID 257649

Reaction equation

HRID 257649 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[N:10]=[N:11][C:12]1[CH:17]=[C:16]([C:18]([CH2:21][CH3:22])([CH3:20])[CH3:19])[CH:15]=[C:14]([C:23]([CH2:26][CH3:27])([CH3:25])[CH3:24])[C:13]=1[OH:28])([O-])=O.[OH-].[Na+].C1C2C(=O)C3C(=CC=CC=3)C=2C=CC=1.O=C[C@@H]([C@H]([C@@H]([C@@H](CO)O)O)O)O.S(=O)(=O)(O)O>O.CO>[OH:28][C:13]1[C:14]([C:23]([CH2:26][CH3:27])([CH3:25])[CH3:24])=[CH:15][C:16]([C:18]([CH2:21][CH3:22])([CH3:20])[CH3:19])=[CH:17][C:12]=1[N:11]1[N:10]=[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]2=[N:1]1

Participants

8

Reactant 5

HCID 1118Sulfuric AcidHCID 10241FluorenoneHCID 14798Sodium HydroxideHCID 1041112-Nitro-2'-hydroxy-3',5'-bis(tert-amyl)azobenzeneHCID 107526(2R,3S,4R,5R)-2,3,4,5,6-pentahydroxyhexanal

Product 1

HCID 33263UV-328Yield 85%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent2×

Conditions

Temperature
20 °C

Procedure

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.

Workup

  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

Sources & evidence

ORD record
ord-a4ed144476a243a9a59083c43dba3788
Source dataset
uspto-grants-1993_11
Patent number
US05262541

Linked notes

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