Hydrochloric Acid → 4-Acetyloxy-3-(3-methylbut-2-enyl)benzoic acid

HRID 1437002Notes

Reaction equation

HRID 1437002 reaction equation
[C:1](OC(=O)C)(=[O:3])[CH3:2].[OH:8][C:9]1[CH:17]=[CH:16][C:12]([C:13]([OH:15])=[O:14])=[CH:11][C:10]=1[CH2:18][CH:19]=[C:20]([CH3:22])[CH3:21].O.Cl>N1C=CC=CC=1>[C:1]([O:8][C:9]1[CH:17]=[CH:16][C:12]([C:13]([OH:15])=[O:14])=[CH:11][C:10]=1[CH2:18][CH:19]=[C:20]([CH3:22])[CH3:21])(=[O:3])[CH3:2]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 7918Acetic AnhydrideHCID 4438524-Hydroxy-3-(3-methylbut-2-en-1-yl)benzoic acid

Product 1

HCID 2211514-Acetyloxy-3-(3-methylbut-2-enyl)benzoic acidYield 51%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

Acetic anhydride (1 mL) was added dropwise to a solution of acid 8 (178 mg, 2.00 mmol) in pyridine (3 mL) at room temperature. After stirring for 48 hours, the mixture was poured into water (6 mL) and acidified to pH=2 by the dropwise addition of 6 M HCl. The suspension was extracted with EtOAc (2×10 mL), and the combined organic fractions were dried (Na2SO4), filtered and concentrated. The residue was purified by chromatography (5:1, hexanes:EtOAc) to afford acetate 9 (223 mg, 51%) as a white solid: 1H NMR (CDCl3, 400 MHz) δ 8.01-7.96 (m, 2H), 7.15 (dd, J=3.5, 8.2 Hz, 1H), 5.24 (tt, J=1.3, 7.2 Hz, 1H), 3.30 (d, J=7.2 Hz, 2H), 2.34 (s, 3H), 1.97 (s, 3H), 1.76 (s, 3H).

Workup

  1. extractionThe suspension was extracted with EtOAc (2×10 mL)
  2. dry with materialthe combined organic fractions were dried (Na2SO4)
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customThe residue was purified by chromatography (5:1, hexanes:EtOAc)

Sources & evidence

ORD record
ord-bd293eb50ad14e18a78c81edd6c5b053
Source dataset
uspto-grants-2009_11
Patent number
US07622451B2

Reaction notes

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