Formic Acid → 3,5-Diacetoxybenzoic Acid

HRID 2236331Notes

Reaction equation

HRID 2236331 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]([CH:8]=[C:9]([OH:11])[CH:10]=1)[C:5]([OH:7])=[O:6].[C:12](OC(=O)C)(=[O:14])[CH3:13].N1[CH:24]=[CH:23]C=CC=1.C(O)=[O:26]>CCOC(C)=O.O>[C:12]([O:1][C:2]1[CH:3]=[C:4]([CH:8]=[C:9]([O:11][C:23](=[O:26])[CH3:24])[CH:10]=1)[C:5]([OH:7])=[O:6])(=[O:14])[CH3:13]

Participants

7

Reactant 4

HCID 284Formic AcidHCID 1049PyridineHCID 74243,5-Dihydroxybenzoic AcidHCID 7918Acetic Anhydride

Product 1

HCID 5398693,5-Diacetoxybenzoic AcidYield 75.3%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 3,5-dihydroxybenzoic acid (7.71 g, 50 mmol) in EtOAc (10 mL) were added acetic anhydride (12.25 mL, 130 mmol) and pyridine (8.08 mL, 100 mmol) in an ice-water bath under a nitrogen atmosphere. The mixture was stirred at 0° C. for 40 min and then stirred at ambient temperature for 4 h. 98% Formic acid (2.36 mL, 60 mmol) was added and the resulting mixture was stirred for 1 h. Then, it was poured into water and extracted with EtOAc. The organic phase was washed with water and brine, dried over Na2SO4, filtered, and evaporated in vacuo. Purification of the residue via recrystallization from n-heptane/EtOAc provided 3,5-diacetoxybenzoic acid (8.97 g, 75.3%) as white solid. Data are: 1H NMR (CDCl3, 300 MHz) δ 12.1 (bs, 1H), 7.73 (d, 2H), 7.21 (t, 1H), 2.32 (s, 6H); 13C NMR (CDCl3, 75 MHz) δ 170.4, 169.0, 151.2, 131.5, 121.3, 121.0, 21.2; mp=161-162° C.; HRMS (EI+) found 238.0475 M+, calcd 238.0477 for C11H10O6; Anal. Calcd for C11H10O6: C, 55.47; H, 4.23. Found: C, 55.62; H, 4.37.

Workup

  1. stirringstirred at ambient temperature for 4 h
  2. stirringthe resulting mixture was stirred for 1 h
  3. extractionextracted with EtOAc
  4. washThe organic phase was washed with water and brine
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. customevaporated in vacuo
  8. customPurification of the residue
  9. customvia recrystallization from n-heptane/EtOAc

Sources & evidence

ORD record
ord-4a02fede73f14a3189e925971c719fdd
Source dataset
uspto-grants-2010_05
Patent number
US07714161B2

Reaction notes

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