Trifluoroacetic acid → 4-(2-Fluoro-4-nitrophenyl)tetrahydro-2H-1,2-thiazine 1,1-dioxide

HRID 1699656Notes

Reaction equation

HRID 1699656 reaction equation
[F:1][C:2]1[CH:7]=[C:6]([N+:8]([O-:10])=[O:9])[CH:5]=[CH:4][C:3]=1[CH:11]1[CH2:16][CH2:15][S:14](=[O:18])(=[O:17])[NH:13][C:12]1=O.[BH4-].[Na+].C1COCC1.FC(F)(F)C(O)=O>CO>[F:1][C:2]1[CH:7]=[C:6]([N+:8]([O-:10])=[O:9])[CH:5]=[CH:4][C:3]=1[CH:11]1[CH2:16][CH2:15][S:14](=[O:18])(=[O:17])[NH:13][CH2:12]1

Participants

6

Reactant 4

HCID 6422Trifluoroacetic acid2×HCID 8028TetrahydrofuranHCID 4311764Sodium borohydrideHCID 183691534-(2-Fluoro-4-nitrophenyl)dihydro-2H-1,2-thiazin-3(4H)-one 1,1-dioxide

Product 1

HCID 183691484-(2-Fluoro-4-nitrophenyl)tetrahydro-2H-1,2-thiazine 1,1-dioxide

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

4-(2-Fluoro-4-nitrophenyl)dihydro-2H-1,2-thiazin-3(4H)-one 1,1-dioxide (2.43 g, 8.44 mmol) and sodium borohydride (3.83 g, 101.3 mmol) are placed under nitrogen and dry THF (70 ml) added. To the ice cooled suspension is added trifluoroacetic acid (7.8 ml, 101.3 mmol) over 5 min. After stirring for 16 hr additional trifluoroacetic acid (20.0 ml, 260 mmol) is added followed by methanol (20 ml). The solution is evaporated and the residue dissolved in ethyl acetate (150 ml) and washed with sodium bicarbonate solution (3×100 ml) and brine (50 ml). Evaporation gives a yellow gum which is chromatographed over silica gel (90 g) eluting with 1-3% methanol-chloroform. The title compound is obtained as a gum (1.99 g, 86%): Calcd for C10H11FN2O4S: C, 43.79; H, 4.04; N, 10.21. Found: C, 43.72; H, 4.07; N, 10.11.

Workup

  1. additionis added
  2. customThe solution is evaporated
  3. dissolutionthe residue dissolved in ethyl acetate (150 ml)
  4. washwashed with sodium bicarbonate solution (3×100 ml) and brine (50 ml)
  5. customEvaporation
  6. customgives a yellow gum which
  7. customis chromatographed over silica gel (90 g)
  8. washeluting with 1-3% methanol-chloroform

Sources & evidence

ORD record
ord-a289be5083914589910dfa3e96fcba95
Source dataset
uspto-grants-2002_02
Patent number
US06348459B1

Reaction notes

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