Sodium borohydride → HCID 58292546, compound

HRID 1798101Notes

Reaction equation

[CH3:1][O:2][C:3](=[O:26])[CH2:4][CH2:5][C:6]([C:8]1[C:13]([B:14]2[O:18]C(C)(C)C(C)(C)[O:15]2)=[CH:12][C:11]([O:23][CH3:24])=[CH:10][C:9]=1[CH3:25])=O.[BH4-].[Na+].C(OB(O)O)C1C=CC=CC=1>CO>[CH3:1][O:2][C:3](=[O:26])[CH2:4][CH2:5][CH:6]1[O:18][B:14]([OH:15])[C:13]2[CH:12]=[C:11]([O:23][CH3:24])[CH:10]=[C:9]([CH3:25])[C:8]1=2

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of 4-[4-methoxy-2-methyl-6-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-4-oxo-butyric acid methyl ester (0.33 g, 0.87 mmol) in MeOH (3 mL) was added NaBH4 (0.073 g, 1.92 mmol) at 0° C. The reaction mixture was stirred at 0° C. for 30 minutes, quenched with 6 N HCl and extracted with EtOAc. The organic extracts were dried and concentrated in vacuo. The residue was dissolved in CH3CN and treated with polymer-bounded benzyl boric acid (2 equiv) for 2 hours. The mixture was filtered, concentrated and purified by silica gel flash column chromatography to give 3-(1-hydroxy-6-methoxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl)-propionic acid methyl ester (0.160 g, 69%). 1H NMR (400 MHz, MeOD-d4) δ 6.98 (s, 1H), 6.80 (s, 1H), 5.25 (m, 1H), 3.80 (s, 3H), 3.60 (s, 3H), 2.50-2.30 (m, 6H), 1.77 (m, 1H).

Workup

customquenched with 6 N HCl
extractionextracted with EtOAc
customThe organic extracts were dried
concentrationconcentrated in vacuo
dissolutionThe residue was dissolved in CH3CN
filtrationThe mixture was filtered
concentrationconcentrated
custompurified by silica gel flash column chromatography

Sources & evidence

ORD record: ord-12bfadfe50c943edb9c57a205c81f5c6
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08343944B2

Reaction notes

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