Ethanol → ethyl 6-[(hydroxyimino)methyl]-2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylate

HRID 722307Notes

Reaction equation

HRID 722307 reaction equation
Cl.[NH2:2][OH:3].[CH:4]([C:6]1[CH:7]=[CH:8][C:9]2[O:14][CH:13]([C:15]([F:18])([F:17])[F:16])[C:12]([C:19]([O:21][CH2:22][CH3:23])=[O:20])=[CH:11][C:10]=2[CH:24]=1)=O.C([O-])(=O)C.[Na+].C(O)C>O.C(OCC)C>[OH:3][N:2]=[CH:4][C:6]1[CH:7]=[CH:8][C:9]2[O:14][CH:13]([C:15]([F:18])([F:17])[F:16])[C:12]([C:19]([O:21][CH2:22][CH3:23])=[O:20])=[CH:11][C:10]=2[CH:24]=1

Participants

7

Reactant 4

HCID 702EthanolHCID 443297Hydroxyamine hydrochlorideHCID 517045Sodium AcetateHCID 21883688ethyl 6-formyl-2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylate

Product 1

HCID 73852042ethyl 6-[(hydroxyimino)methyl]-2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylateYield 55%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 3283Diethyl EtherSolvent

Procedure

A 50 mL round bottom flask was charged with hydroxylamine HCl (0.255 g, 3.67 mmol), ethyl 6-formyl-2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylate (Example 75, Step 1) (1.00 g, 3.34 mmol), sodium acetate (0.301 g, 3.67 mmol), ethanol (10 mL), and H2O (2 mL). The reaction was stirred at room temperature for 18 hours, then diluted with H2O and diethyl ether. The layers were separated and the organic phase washed with H2O, brine, dried over MgSO4, filtered, and concentrated in vacuo yielding an orange semi-crystalline mass. Recrystallization of this solid from hot ethyl acetate and isooctane yielded the oxime (0.578 g, 55%): mp 113.0–116.2° C. 1H NMR (acetone-d6/300 MHz) 10.46 (s, ca.1 exch.), 8.11 (s, 2H), 7.92 (s, 1H), 7.72 (d, 1H, J=2 Hz)), 7.68 (dd, 1H, J=8.5, 2.0 Hz), 7.07 (d, 1H, J=8.5 Hz), 5.89 (q, 1H, J=7.1 Hz), 4.43−4.22 (m, 2H), 1.34 9t, 3H, J=7.3 Hz). FABLRMS m/z 316 (M+H). EIHRMS m/z 315.0719 (M+, Calc'd 315.0733). Anal. Calc'd for C14H12F3N1O4: C, 53.34; H, 3.84; N 4.44. Found: C, 53.85; H, 3.90; N, 4.19.

Workup

  1. customThe layers were separated
  2. washthe organic phase washed with H2O, brine
  3. dry with materialdried over MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customyielding an orange semi-crystalline mass
  7. customRecrystallization of this solid from hot ethyl acetate and isooctane

Sources & evidence

ORD record
ord-54ba110f70484f6aa98b3300006c61d5
Source dataset
uspto-grants-2006_11
Patent number
US07138411B2

Reaction notes

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