Sodium borohydride → Methyl 4-(2-hydroxyethoxy)salicylate
Reaction equation
[CH3:1][O:2][C:3](=[O:15])[C:4]1[CH:9]=[CH:8][C:7]([O:10][CH2:11][CH:12]=C)=[CH:6][C:5]=1[OH:14].[BH4-].[Na+].C[OH:19].C(Cl)Cl>>[CH3:1][O:2][C:3](=[O:15])[C:4]1[CH:9]=[CH:8][C:7]([O:10][CH2:11][CH2:12][OH:19])=[CH:6][C:5]=1[OH:14]Participants
Procedure
A solution of 4-allyloxy-2-hydroxy-benzoic acid methyl ester(10.952 g, 52.6 mmol) in methanol/methylene chloride (1/1) (300 mL) was cooled to −40° C. then ozone was bubbled through the reaction mixture for 50 minutes. The solution was then purged with nitrogen for 20 minutes, sodium borohydride (2.643 g, 69.86 mmol) was added and warmed to room temperature over 1 hour. The reaction was quenched by the addition of water (20 mL), poured into brine and extracted with ethyl acetate. The combined organics were dried over anhydrous magnesium sulfate and concentrated in vacuo. The residue was purified by flash chromatography using ethyl acetate/hexanes (30/70 to 40/60) to afford 2-hydroxy-4-(2-hydroxy-ethoxy)-benzoic acid methyl ester (9.745 g, 87%) as a white solid. 1H NMR (300 MHz, CDCl3); δ 11.00 (s, 1H), 7.75 (d, 2H), 6.46 (m, 2H), 4.11 (t, 2H), 3.98 (t, 2H), 3.93 (s, 3H), 1.90 (bs, 1H).
Workup
- customozone was bubbled through the reaction mixture for 50 minutes
- customThe solution was then purged with nitrogen for 20 minutes
- customThe reaction was quenched by the addition of water (20 mL)
- additionpoured into brine
- extractionextracted with ethyl acetate
- dry with materialThe combined organics were dried over anhydrous magnesium sulfate
- concentrationconcentrated in vacuo
- customThe residue was purified by flash chromatography
Sources & evidence
- ORD record
- ord-a8c7aa23100b49f59ee42ac9459a4046
- Source dataset
- uspto-grants-2008_09
- Patent number
- US07420083B2
Reaction notes
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