Trifluoroacetic acid → 4-((2,2,2-Trifluoroethyl)amino)-2-(trifluoromethyl)benzonitrile

HRID 2109078Notes

Reaction equation

HRID 2109078 reaction equation
[NH2:1][C:2]1[CH:9]=[CH:8][C:5]([C:6]#[N:7])=[C:4]([C:10]([F:13])([F:12])[F:11])[CH:3]=1.[BH3-]C#N.[Na+].[C:18](O)([C:20]([F:23])([F:22])[F:21])=O.[H][H].O.FC(F)(F)C=O.C([O-])(O)=O.[Na+]>C(Cl)Cl>[F:21][C:20]([F:23])([F:22])[CH2:18][NH:1][C:2]1[CH:9]=[CH:8][C:5]([C:6]#[N:7])=[C:4]([C:10]([F:11])([F:12])[F:13])[CH:3]=1

Participants

8

Reactant 6

HCID 6422Trifluoroacetic acidHCID 516892Sodium Bicarbonate2×HCID 5221704-Amino-2-(trifluoromethyl)benzonitrileHCID 27813662,2,2-Trifluoroacetaldehyde hydrateHCID 5003444Sodium cyanoborohydrideHCID 178418361HCID 178418361, compound

Product 1

HCID 431385374-((2,2,2-Trifluoroethyl)amino)-2-(trifluoromethyl)benzonitrileYield 95%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a slurry of 4-amino-2-(trifluoromethyl)benzonitrile (30.09 g, 162 mmol) and NaBH3CN (21.35 g, 340 mmol) in CH2Cl2 (160 mL) at ice bath temperature was added neat TFA (160 mL, 2.08 mol), dropwise at a rate such that the internal temperature remained below 5° C. (CAUTION: exothermic reaction with hydrogen gas evolution). Trifluoroacetaldehyde hydrate (52.2 g; 405 mmol) was then added over 5 minutes (CAUTION: slightly exothermic reaction, with gas evolution). After 41 h, the mixture was slowly poured into satd NaHCO3 (1 L) at 0° C. The mixture was then completely neutralized by portionwise addition of solid NaHCO3. The mixture was stirred 30 min and precipitated solids were collected by filtration. Organic and aqueous phases of the filtrate were separated, and the aqueous layer was extracted with CH2Cl2 (3×150 mL). Combined organic extracts were concentrated to dryness, combined with the solids collected previously, dissolved in EtOAc, washed (H2O, brine), dried over Na2SO4, filtered through a short pad of Celite and concentrated to dryness. Recrystallization from EtOAc/hexanes yielded 32.61 g (95%) of the title compound as slightly tan crystalline plates: 1H NMR (300 MHz, CD3OD) δ 7.59 (d, J=8.8 Hz, 1H), 7.05 (d, J=2.2 Hz, 1H), 6.92 (dd, J=8.7, 2.4 Hz, 1H), 3.92 (q, J=9.2 Hz, 2H).

Workup

  1. customremained below 5° C.
  2. customslightly exothermic reaction
  3. customprecipitated solids
  4. filtrationwere collected by filtration
  5. customOrganic and aqueous phases of the filtrate were separated
  6. extractionthe aqueous layer was extracted with CH2Cl2 (3×150 mL)
  7. concentrationCombined organic extracts were concentrated to dryness
  8. customcollected previously
  9. dissolutiondissolved in EtOAc
  10. washwashed (H2O, brine)
  11. dry with materialdried over Na2SO4
  12. filtrationfiltered through a short pad of Celite
  13. concentrationconcentrated to dryness
  14. customRecrystallization from EtOAc/hexanes

Sources & evidence

ORD record
ord-7ff0a6bb297845bbbeb57abb17cadc95
Source dataset
uspto-grants-2009_04
Patent number
US07514470B2

Reaction notes

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