Sodium borohydride → HCID 21883638, compound

HRID 650153Notes

Reaction equation

HRID 650153 reaction equation
[CH:1]([C:3]1[CH:4]=[CH:5][C:6]2[O:11][CH:10]([C:12]([F:15])([F:14])[F:13])[C:9]([C:16]([OH:18])=[O:17])=[CH:8][C:7]=2[CH:19]=1)=[O:2].[BH4-].[Na+]>C(O)C>[OH:2][CH2:1][C:3]1[CH:4]=[CH:5][C:6]2[O:11][CH:10]([C:12]([F:14])([F:15])[F:13])[C:9]([C:16]([OH:18])=[O:17])=[CH:8][C:7]=2[CH:19]=1

Participants

4

Reactant 2

HCID 4311764Sodium borohydride2×HCID 10016051HCID 10016051, compound

Product 1

HCID 21883638HCID 21883638, compoundYield 31.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a chilled (ice bath), stirred solution of 6-formyl-2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylic acid (Example 75, Step 2) (0.133 g, 0.489 mmol) in THE (1 mL) and ethanol (1 mL) in a 10 mL round bottom flask was added NaBH4 (0.020 g, 0.528 mmol) in two portions. The reaction was allowed to warm to room temperature and more NaBH4 (0.050 g, 1.322 mmol) was added. The total reaction time was 3 hours. The reaction was quenched with aqueous HCl (1 N solution) and was extracted with chloroform. The organic phase was dried over MgSO4, filtered and concentrated in vacuo yielding a foam. This crude product was purified by flash chromatography (silica gel 60, eluant 1:1, hexane-ethyl Acetate with 2% acetic acid). The product collected from the chromatography was recrystallized from hexanes and ethyl acetate, and collected by vacuum filtration yielding the title compound (0.042 g, 31%) as a very pale yellow powder: mp 177.5-180.8° C. 1H NMR (acetone-d6/300 MHz) 7.89 (s, 1H), 7.44 (s, 1H), 7.41 (d, 1H, J=8.3 Hz), 6.99 (d, 1H, J=8.3 Hz), 5.80 (q, 1H, J=7.3 Hz), 4.59 (s, 2H). FABLRMS m/z 275 (M+H). EIHRMS m/z 274.0417 (M+, Calc'd 274.0453). Anal. Calc'd for C12H9F3O4: C, 52.57; H, 3.31. Found: C, 52.43; H, 3.34.

Workup

  1. temperatureTo a chilled (ice bath)
  2. customThe reaction was quenched with aqueous HCl (1 N solution)
  3. extractionwas extracted with chloroform
  4. dry with materialThe organic phase was dried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customyielding a foam
  8. customThis crude product was purified by flash chromatography (silica gel 60, eluant 1:1, hexane-ethyl Acetate with 2% acetic acid)
  9. customThe product collected from the chromatography
  10. customwas recrystallized from hexanes and ethyl acetate
  11. filtrationcollected by vacuum filtration

Sources & evidence

ORD record
ord-d1880f877d95498ebcccbf40087412ef
Source dataset
uspto-grants-2001_08
Patent number
US06271253B1

Reaction notes

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