Hydroxyamine hydrochloride → HCID 90455740, compound

HRID 2202127Notes

Reaction equation

HRID 2202127 reaction equation
C(O/[CH:4]=[C:5](\[C:13]1[CH:18]=[CH:17][C:16]([F:19])=[CH:15][CH:14]=1)/[C:6](=[O:12])[C:7]([O:9][CH2:10][CH3:11])=[O:8])C.Cl.[NH2:21]O>C(O)C>[F:19][C:16]1[CH:17]=[CH:18][C:13]([C:5]2[CH:4]=[N:21][O:12][C:6]=2[C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:14][CH:15]=1

Participants

4

Reactant 2

HCID 443297Hydroxyamine hydrochlorideHCID 117611668HCID 117611668, compound

Product 1

HCID 90455740HCID 90455740, compoundYield 26%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of (E)-ethyl 4-ethoxy-3-(4-fluorophenyl)-2-oxobut-3-enoate (1.5 g, 5.63 mmol, 1.00 equiv) and hydroxylamine hydrochloride (2 g, 28.99 mmol, 5.15 equiv) in ethanol (10 mL) was refluxed for 3 h. The reaction mixture was cooled to room temperature and then quenched by 15 mL of saturated sodium bicarbonate solution. The resulting mixture was extracted with 2×10 mL of ethyl acetate. The combined organic layers was dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was purified on a silica gel column eluted with 0-10% of ethyl acetate in petroleum ether to yield 340 mg (26%) of ethyl 4-(4-fluorophenyl)-1,2-oxazole-5-carboxylate as a yellow oil. 1H-NMR (300 MHz, CDCl3): δ 8.57 (s, 1H), 7.47-7.43 (m, 2H), 7.11-7.03 (m, 2H), 4.43 (q, J=7.2 Hz, 2H), 1.30 (t, J=7.2 Hz, 3H) ppm.

Workup

  1. customquenched by 15 mL of saturated sodium bicarbonate solution
  2. extractionThe resulting mixture was extracted with 2×10 mL of ethyl acetate
  3. dry with materialThe combined organic layers was dried over anhydrous sodium sulfate
  4. concentrationconcentrated under vacuum
  5. customThe residue was purified on a silica gel column
  6. washeluted with 0-10% of ethyl acetate in petroleum ether

Sources & evidence

ORD record
ord-61397a3f62cb4de0ba1b20b59bb1d1c4
Source dataset
uspto-grants-2016_06
Patent number
US09365527B2

Reaction notes

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