Benzene → 3-Hydroxy-5-keto-4-phenylazo-3-cyclohexenecarboxylic acid methyl ester

HRID 2398066Notes

Reaction equation

HRID 2398066 reaction equation
[OH:1][C:2]1[CH2:3][CH:4]([C:17]([OH:19])=[O:18])[CH2:5][C:6](=[O:16])[C:7]=1[N:8]=[N:9][C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1.CO.[CH:22]1C=CC=CC=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>O>[CH3:22][O:18][C:17]([CH:4]1[CH2:3][C:2](=[O:1])[C:7]([N:8]=[N:9][C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)=[C:6]([OH:16])[CH2:5]1)=[O:19]

Participants

6

Reactant 4

HCID 241BenzeneHCID 887MethanolHCID 6101p-Toluenesulfonic acidHCID 1355835033-Hydroxy-5-keto-4-phenylazo-3-cyclohexenecarboxylic acid

Product 1

HCID 1360563743-Hydroxy-5-keto-4-phenylazo-3-cyclohexenecarboxylic acid methyl ester

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

60 G. of 3-hydroxy-5-keto-4-phenylazo-3-cyclohexene-carboxylic acid, 200 ml. of methanol, 1200 ml. of benzene and 5 g. of p-toluenesulfonic acid were heated together at reflux for 18 hours on a water separator. After cooling, the solution was washed with 500 ml. of a 5% sodium bicarbonate solution, washed with water, dried and evaporated. The residue was dissolved in ethyl acetate and purified on an aluminum oxide column (500 g., activity stage I). After evaporation of the ethyl acetate, there was obtained 3-hydroxy-5-keto-4-phenylazo-3-cyclohexenecarboxylic acid methyl ester of melting point 144° C. (from benzene/petroleum ether).

Workup

  1. temperatureAfter cooling
  2. washthe solution was washed with 500 ml
  3. washof a 5% sodium bicarbonate solution, washed with water
  4. customdried
  5. customevaporated
  6. dissolutionThe residue was dissolved in ethyl acetate
  7. custompurified on an aluminum oxide column (500 g., activity stage I)
  8. customAfter evaporation of the ethyl acetate

Sources & evidence

ORD record
ord-c0a53e7041de484e8468513e11c4954d
Source dataset
uspto-grants-1977_05
Patent number
US04024145

Reaction notes

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