Acetic Anhydride → 3-Acetoxy-5-hydroxy-4-phenylazo-benzoic acid methyl ester

HRID 414523Notes

Reaction equation

HRID 414523 reaction equation
[CH3:1][O:2][C:3](=[O:20])[C:4]1[CH:9]=[C:8]([OH:10])[C:7]([N:11]=[N:12][C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)=[C:6]([OH:19])[CH:5]=1.[C:21](OC(=O)C)(=[O:23])[CH3:22]>C(O)(=O)C>[CH3:1][O:2][C:3](=[O:20])[C:4]1[CH:9]=[C:8]([OH:10])[C:7]([N:11]=[N:12][C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)=[C:6]([O:19][C:21](=[O:23])[CH3:22])[CH:5]=1

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 1360597863,5-Dihydroxy-4-phenylazo-benzoic acid methyl ester

Product 1

HCID 1361762643-Acetoxy-5-hydroxy-4-phenylazo-benzoic acid methyl ester

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A mixture of 27 g. of 3,5-dihydroxy-4-phenylazo-benzoic acid methyl ester, 250 ml. of glacial acetic acid and 21 g. of acetic anhydride was stirred at 100° C. for 3 hours, complete solution occurring. The resulting solution was evaporated to dryness under reduced pressure. The residue was taken up in methanol and again evaporated to dryness. The residue was recrystallized from dimethylformamide/methanol and there was obtained 3-acetoxy-5-hydroxy-4-phenylazo-benzoic acid methyl ester having a melting point of 162° C.

Workup

  1. additionA mixture of 27 g
  2. customThe resulting solution was evaporated to dryness under reduced pressure
  3. customagain evaporated to dryness
  4. customThe residue was recrystallized from dimethylformamide/methanol

Sources & evidence

ORD record
ord-d88ef3528c3d4020bb59912c19ba67d8
Source dataset
uspto-grants-1988_12
Patent number
US04792557

Reaction notes

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