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

HRID 2166258Notes

Reaction equation

HRID 2166258 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]([CH3:21])([CH3:20])[CH3:19])[CH:15]=[CH:14][C:13]=1[OH:22])([O-])=[O:2].[OH-].[Na+].C1C2C(=O)C3C(=CC=CC=3)C=2C=CC=1.N(C1C=CC=CC=1)=NC1C=CC=CC=1.S(=O)(=O)(O)O>O.C(O)(CC)C>[OH:22][C:13]1[CH:14]=[CH:15][C:16]([C:18]([CH3:21])([CH3:20])[CH3:19])=[CH:17][C:12]=1[N:11]1[N+:1]([O-:2])=[C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]2=[N:10]1

Participants

8

Reactant 5

HCID 1118Sulfuric AcidHCID 2272AzobenzeneHCID 10241FluorenoneHCID 14798Sodium HydroxideHCID 1355145822-Nitro-2'-hydroxy-5'-t-butylazobenzene

Product 1

HCID 139071722-(2-hydroxy-5-t-butylphenyl)benzotriazole-N-oxideYield 82.3%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 6568(+-)-2-ButanolSolvent

Conditions

Temperature
65 °C

Procedure

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%.

Workup

  1. temperatureThereafter, the mixture was cooled to 50° C.
  2. customreaction
  3. temperatureThe neutralized reaction liquor was then cooled to 20° C.
  4. customlower to precipitate a crystal
  5. customThe crystal thus obtained
  6. filtrationwas filtered
  7. customto separate the crystal
  8. washthe separated crystal was then fully washed with water and further with a small amount of methanol
  9. customThe washed crystal was then dried

Sources & evidence

ORD record
ord-b28b8c8be4354b368e3d46aae58fc655
Source dataset
uspto-grants-1990_07
Patent number
US04943637

Reaction notes

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