3-Chloro-4-hydroxybenzoic acid hemihydrate → Methyl 3-chloro-4-hydroxybenzoate
Reaction equation
O.[Cl:2][C:3]1[CH:4]=[C:5]([CH:9]=[CH:10][C:11]=1[OH:12])[C:6]([OH:8])=[O:7].Cl[C:14]1C=C(C=CC=1O)C(O)=O>CO>[CH3:14][O:7][C:6](=[O:8])[C:5]1[CH:9]=[CH:10][C:11]([OH:12])=[C:3]([Cl:2])[CH:4]=1Participants
3
Reactant 1
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 55 °C
Procedure
To a solution of 3-chloro-4-hydroxy-benzoic acid hemihydrate (9.08 g, 50 mmol) in methanol (150 mL) is added slowly (conc)sulfuric acid (22.5 mL). The resulting solution is heated to 55° C. and stirred 2 hours then cooled to 20° C. Poured solution into ice and extracted with ether. The organic is washed with brine, dried over MgSO4 and concentrated. The residue is purified by flash chromatography (eluting with 30% ethyl acetate in hexanes) to give 9.5 g of title compound as a white crystalline solid. 1H NMR (CDCl3) δ 3.90 (s, 3H), 7.06 (d, J=9 Hz, 1H), 7.88 (dd, J=9, 2 Hz, 1H), 8.05 (d, J=2 Hz, 1H). MS (EI) m/z 186/188 (M+, Cl).
Workup
- temperaturethen cooled to 20° C
- extractionPoured solution into ice and extracted with ether
- washThe organic is washed with brine
- dry with materialdried over MgSO4
- concentrationconcentrated
- customThe residue is purified by flash chromatography (eluting with 30% ethyl acetate in hexanes)
Sources & evidence
- ORD record
- ord-c2ce659aa8634e6b83e6135780d6d45d
- Source dataset
- uspto-grants-2003_04
- Patent number
- US06541505B1
Reaction notes
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