Hydrochloric Acid → HCID 58292817, compound

HRID 1798093Notes

Reaction equation

HRID 1798093 reaction equation
[CH2:1]([O:3][C:4](=[O:18])[CH2:5][C@H:6]1[O:10][B:9]([OH:11])[C:8]2[CH:12]=[C:13]([OH:17])[CH:14]=[C:15]([CH3:16])[C:7]1=2)[CH3:2].[C:19]([O-])([O-])=O.[Cs+].[Cs+].CI.Cl>CN(C=O)C>[CH2:1]([O:3][C:4](=[O:18])[CH2:5][C@H:6]1[O:10][B:9]([OH:11])[C:8]2[CH:12]=[C:13]([O:17][CH3:19])[CH:14]=[C:15]([CH3:16])[C:7]1=2)[CH3:2]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 6328Methyl iodideHCID 10796Cesium carbonateHCID 58292773HCID 58292773, compound

Product 1

HCID 58292817HCID 58292817, compoundYield 35%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of (3R)-(1,6-dihydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl)-acetic acid ethyl ester (2.0 g, 7.9 mmol) in anhydrous DMF (20 mL) were added Cs2CO3 (15.4 g, 47.4 mmol) and methyl iodide (1.43 g, 9.6 mmol) at 0° C. After stirring at room temperature for 4 hours the reaction mixture was cooled to 0° C. and acidified to pH 2 with concentrated HCl. The mixture was extracted with ethyl acetate and the organic extracts were washed with water, brine, dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica gel flash column chromatography (30-100% EtOAc in hexane) to give (3R)-(1-hydroxy-6-methoxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl)-acetic acid ethyl ester as a yellow foam (0.7 g, 35%). 1H NMR 400 MHz (DMSO-d6) δ9.12 (s, 1H), 7.07 (d, J=2.0 Hz, 1H), 6.85 (d, J=2.0 Hz, 1H), 5.46 (dd, J=9.2, 2.4 Hz, 1H), 4.09-4.03 (m, 2H), 3.74 (s, 3H), 3.17-3.07 (m, 1H), 2.26 (s, 3H), 2.23-2.17 (m, 1H), 1.16-1.12 (m, 3H).

Workup

  1. temperaturewas cooled to 0° C.
  2. extractionThe mixture was extracted with ethyl acetate
  3. washthe organic extracts were washed with water, brine
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated in vacuo
  6. customThe residue was purified by silica gel flash column chromatography (30-100% EtOAc in hexane)

Sources & evidence

ORD record
ord-78dbd635f2af44a1bfdc8da8da8897e4
Source dataset
uspto-grants-2013_01
Patent number
US08343944B2

Reaction notes

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