Ethyl trifluoroacetate → 1-(6-Fluorobenzothiazol-2-yl)-4,4,4-trifluorobutane-1,3-dione

HRID 369078Notes

Reaction equation

HRID 369078 reaction equation
C[O-].[Na+].[F:4][C:5]([F:12])([F:11])[C:6]([O:8]CC)=O.[C:13]([C:16]1[S:17][C:18]2[CH:24]=[C:23]([F:25])[CH:22]=[CH:21][C:19]=2[N:20]=1)(=[O:15])[CH3:14]>C1COCC1>[F:25][C:23]1[CH:22]=[CH:21][C:19]2[N:20]=[C:16]([C:13](=[O:15])[CH2:14][C:6](=[O:8])[C:5]([F:4])([F:11])[F:12])[S:17][C:18]=2[CH:24]=1

Participants

5

Reactant 3

HCID 9794Ethyl trifluoroacetateHCID 10942334Sodium MethoxideHCID 232854442-Acetyl-6-fluorobenzothiazole

Product 1

HCID 232853611-(6-Fluorobenzothiazol-2-yl)-4,4,4-trifluorobutane-1,3-dioneYield 42.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

To a suspension of sodium methoxide (0.581 mg, 1.08 mmol) in THF (15 ml) was added a solution of ethyl trifluoroacetate (1.456 g, 10.2 mmol) in THF (7 ml) under nitrogen atmosphere. To the resulting mixture was added a solution of 2-acetyl-6-fluorobenzothiazole (2.00 g, 10.2 mmol) in THF (25 ml) dropwise along with ice cooling. The mixture was stirred at room temperature for 1.5 hours, and then concentrated. The resultant residue was subjected to purification using column chromatography on silica gel to afford 1-(6-fluorobenzothiazol-2-yl)-4,4,4-trifluorobutane-1,3-dione (1.26 g, 42%). NMR(CDCl3 -DMSO-d6) δ: 6.85 (1H, s), 7.23 (1H, app dt, J=2.6 Hz, 8.9 Hz), 7.59 (1H, dd, J=2.6 Hz, 8.2 Hz), 8.05 (1H, dd, J=4.6 Hz, 8.9 Hz); mp 175-178° C.

Workup

  1. concentrationconcentrated
  2. customThe resultant residue was subjected to purification

Sources & evidence

ORD record
ord-c01aee098cb943929e2eb966b91b86a8
Source dataset
uspto-grants-2000_10
Patent number
US06136831

Reaction notes

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