Trifluoroacetic acid → Ethyl[2-oxo-5-[(trifluoromethyl)oxy]-1,3-benzoxazol-3(2H)-yl]acetate

HRID 2114406Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2114406
[F:1][C:2]([F:15])([F:14])[O:3][C:4]1[CH:5]=[CH:6][C:7]2[O:11][C:10](=[O:12])[NH:9][C:8]=2[CH:13]=1.[H-].[Na+].Br[CH2:19][C:20]([O:22][CH2:23][CH3:24])=[O:21].FC(F)(F)C(O)=O>O1CCCC1.CC#N.O>[O:12]=[C:10]1[N:9]([CH2:19][C:20]([O:22][CH2:23][CH3:24])=[O:21])[C:8]2[CH:13]=[C:4]([O:3][C:2]([F:1])([F:14])[F:15])[CH:5]=[CH:6][C:7]=2[O:11]1

Komponenten

7

Edukt 4

HCID 6422Trifluoroacetic acidHCID 7748Ethyl bromoacetateHCID 24758Sodium hydrideHCID 574186752(3H)-Benzoxazolone, 5-(trifluoromethoxy)-

Produkt 1

HCID 57488864Ethyl[2-oxo-5-[(trifluoromethyl)oxy]-1,3-benzoxazol-3(2H)-yl]acetateAusbeute 62 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 8028TetrahydrofuranLösungsmittel2×HCID 18373917Acetonitrile--water (1/1)Lösungsmittel

Versuchsvorschrift

A solution of 5-[(trifluoromethyl)oxy]-1,3-benzoxazol-2(3H)-one (1.12 g, 5.1 mmol) dissolved in 6 mL of anhydrous tetrahydrofuran was added drop-wise to a mixture of sodium hydride (60% by weight in mineral oil, 0.22 g, 5.6 mmol) suspended in 11 mL of anhydrous tetrahydrofuran under argon. The mixture was allowed to stir at room temperature for 10 minutes and then ethyl bromoacetate (0.68 mL, 6.1 mmol) was added to the mixture and stirred vigorously for 18 hours before it was determined to be complete by LCMS (two Aquasil C18, 20×1 mm columns were run in sequence, 4 minutes at 0.1 mL/min, 1-99% CH3CN/H2O with 0.018% trifluoroacetic acid, ES) Rt=2.8 min and m/e 306 [M+1]+. The reaction was quenched by adding 5 mL of a 4 M solution of hydrochloric acid in dioxane. After allowing the mixture to stir for one hour, all of the volatiles were removed by rotary evaporation, and the crude residue was purified by silica gel chromatography (40 g Redisep column, silica, 40 um, 60 Å, 35 mL/min, A: methylene chloride, B: methanol, B: 0% to 35% over 30 min; detection at 214 nm) to give ethyl [2-oxo-5-[(trifluoromethyl)oxy]-1,3-benzoxazol-3(2H)-yl]acetate (0.96 g, 3.0 mmol, 62%) of a pink oil. MS (ES) m/e 306 [M+1]+.

Aufarbeitung

  1. additionwas added drop-wise
  2. stirringstirred vigorously for 18 hours before it
  3. customThe reaction was quenched
  4. additionby adding 5 mL of a 4 M solution of hydrochloric acid in dioxane
  5. stirringto stir for one hour
  6. customall of the volatiles were removed by rotary evaporation
  7. customthe crude residue was purified by silica gel chromatography (40 g Redisep column, silica, 40 um, 60 Å, 35 mL/min
  8. waitA: methylene chloride, B: methanol, B: 0% to 35% over 30 min

Quellen und Nachweise

ORD-Eintrag
ord-2f3a9993c5d14df8866808299167db13
Quelldatensatz
uspto-grants-2008_10
Patentnummer
US07432258B2

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