Cesium carbonate → HCID 67252450, compound

HRID 1798220Notes

Reaction equation

HRID 1798220 reaction equation
[CH2:1]([O:3][C:4](=[O:18])[CH2:5][CH: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(=O)([O-])[O-].[Cs+].[Cs+].Cl[C:26]1[N:31]=[C:30]([C:32]#[N:33])[CH:29]=[N:28][CH:27]=1>CN(C=O)C>[CH2:1]([O:3][C:4](=[O:18])[CH2:5][CH:6]1[O:10][B:9]([OH:11])[C:8]2[CH:12]=[C:13]([O:17][C:26]3[CH:27]=[N:28][CH:29]=[C:30]([C:32]#[N:33])[N:31]=3)[CH:14]=[C:15]([CH3:16])[C:7]1=2)[CH3:2]

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 813036-Chloropyrazine-2-carbonitrileHCID 58292549Ethyl 2-(1,6-dihydroxy-4-methyl-1,3-dihydrobenzo[c][1,2]oxaborol-3-yl)acetate

Product 1

HCID 67252450HCID 67252450, compound

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of (1,6-dihydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl)-acetic acid ethyl ester (1.6 g, 6.4 mmol) in anhydrous DMF (15 mL) was added cesium carbonate (5.2 g, 16.0 mmol) and 6-chloro-pyrazine-2-carbonitrile (0.89 g, 6.4 mmol). The resulting mixture was stirred at room temperature overnight then quenched with crushed ice. The pH was adjusted to 2 with 6M HCl and the mixture extracted with EtOAc (2×200 mL). The organic extracts were washed with water, brine, dried over Na2SO4, filtered, and concentrated in vacuo. The residue was purified by silica gel flash column chromatography (0-75% EtOAc in hexane) to give 6-(6-cyano-pyrazin-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl)-acetic acid ethyl ester (1.6 g, 71%). 1H NMR 400 MHz (DMSO-d6) δ 9.30 (s, 1H), 8.93 (s, 1H), 8.90 (s, 1H), 7.33 (s, 1H), 7.18 (s, 1H), 5.58 (m, 1H), 4.05 (q, J=7.2, 2H), 3.17 (m, 1H), 2.40 (m, 1H), 2.33 (s, 3H), 1.13 (t, J=6.8 Hz, 3H).

Workup

  1. customthen quenched with crushed ice
  2. extractionthe mixture extracted with EtOAc (2×200 mL)
  3. washThe organic extracts were washed with water, brine
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customThe residue was purified by silica gel flash column chromatography (0-75% EtOAc in hexane)
  8. customto give 6-(6-cyano-pyrazin-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl)-acetic acid ethyl ester (1.6 g, 71%)

Sources & evidence

ORD record
ord-f7d6cbb5205b4c969ff2198fdc8395a9
Source dataset
uspto-grants-2013_01
Patent number
US08343944B2

Reaction notes

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