4-Methyl-2-[2-(2-nitrophenyl)diazenyl]phenol → Drometrizole

HRID 1856412Notes

Reaction equation

HRID 1856412 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]([CH3:18])[CH:15]=[CH:14][C:13]=1[OH:19])([O-])=O>[OH-].[Na+].O.C(O)(C)C.[Ni].[Mo]>[OH:19][C:13]1[CH:14]=[CH:15][C:16]([CH3:18])=[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

7

Reactant 1

HCID 740294-Methyl-2-[2-(2-nitrophenyl)diazenyl]phenol

Product 1

HCID 17113Drometrizole

Reagents, catalysts & solvents 5

HCID 935NickelCatalystHCID 23932MolybdenumCatalystHCID 962WaterSolvent2×HCID 3776IsopropanolSolventHCID 14798Sodium HydroxideSolvent

Procedure

When using the procedure of Example 5, 48.7 grams (0.18 mole) of 2-nitro-2'-hydroxy-5'-methylazobenzene (95% pure) was dissolved in a solution of 9 grams of sodium hydroxide in 30 grams of water and 45 grams of isopropanol, and a total of 7.0 grams of a 50% slurry in water of molybdenum-promoted Raney nickel catalyst (W. R. Grace Raney No. 30) were added in two equal 3.5 grams portions at the start and at the half way point of the hydrogenation, the product, 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole was obtained in very high yield after removal of the suspended nickel catalyst by filtration and acidification of the filtrate to a pH value of less than 4 using aqueous sulfuric acid.

Workup

  1. addition30) were added in two equal 3.5 grams portions at the start and at the half way point of the hydrogenation

Sources & evidence

ORD record
ord-51a8103c0c734634871894bc110764bb
Source dataset
uspto-grants-1980_08
Patent number
US04219480

Reaction notes

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