Water → 7-Fluoro-6-nitro-4-(prop-2-yn-1-yl)-2H-1,4-benzoxazin-3(4H)-one

HRID 1940487Notes

Reaction equation

HRID 1940487 reaction equation
[F:1][C:2]1[C:12]([N+:13]([O-:15])=[O:14])=[CH:11][C:5]2[NH:6][C:7](=[O:10])[CH2:8][O:9][C:4]=2[CH:3]=1.[H-].[Na+].[CH2:18](Br)[C:19]#[CH:20].O>CN(C=O)C.CCOC(C)=O>[F:1][C:2]1[C:12]([N+:13]([O-:15])=[O:14])=[CH:11][C:5]2[N:6]([CH2:20][C:19]#[CH:18])[C:7](=[O:10])[CH2:8][O:9][C:4]=2[CH:3]=1

Participants

7

Reactant 4

HCID 962WaterHCID 7842Propargyl bromideHCID 24758Sodium hydrideHCID 137312977-Fluoro-6-nitro-2H-1,4-benzoxazin-3(4H)-one

Product 1

HCID 137312997-Fluoro-6-nitro-4-(prop-2-yn-1-yl)-2H-1,4-benzoxazin-3(4H)-one

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a stirred solution of the compound of Step C, Example 3, (4.0 gm, 18.86 mmol) in DMF (100 mL), under N2, at 5° C. (ice-bath) was added sodium hydride (60% in mineral oil, 753.0 mg, 18.86 mmol) portionwise. When gas evolution stopped, propargyl bromide (80%, 2.24 gm, 18.86 mmol) was added dropwise. The dark solution was stirred at room temperature for 17 hours. The reaction was carefully poured into water (150 mL) and EtOAc (600 mL) was added. The organic layer was separated and evaporated to dryness. The residue was chromatographed on silica gel using 25% of ethyl acetate in hexane as eluent. Fractions of compound of interest were combined and evaporated to dryness to yield the title compound of Step D, Example 3, as a yellow solid (2.7 gm), 57%; m.p. 105°-107° C.; IR (nujol, cm-1): 1695.3 (C=O) and 2120.6 (C≡C); 1H NMR δ: 4.76-4.81 (m,4H), 6.91-6.94 (d,1H), 7.97-7.98 (d,1H), 2.35 (s,1H).

Workup

  1. additionwas added
  2. customThe organic layer was separated
  3. customevaporated to dryness
  4. customThe residue was chromatographed on silica gel using 25% of ethyl acetate in hexane as eluent
  5. customevaporated to dryness

Sources & evidence

ORD record
ord-78a5a8084831454ebdc54f0675e66876
Source dataset
uspto-grants-1997_12
Patent number
US05700761

Reaction notes

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