Tributylamine → Pentoxazone

HRID 2289025Notes

Reaction equation

HRID 2289025 reaction equation
[Cl:1][C:2]1[C:7]([O:8][CH:9]2[CH2:13][CH2:12][CH2:11][CH2:10]2)=[CH:6][C:5]([NH:14][C:15](=O)[O:16]CC)=[C:4]([F:20])[CH:3]=1.C(O[C:24]([CH3:33])([CH3:32])[CH:25]([OH:31])[C:26]([O:28]CC)=O)C.C(N(CCCC)CCCC)CCC>C1(C)C=CC=CC=1>[Cl:1][C:2]1[C:7]([O:8][CH:9]2[CH2:10][CH2:11][CH2:12][CH2:13]2)=[CH:6][C:5]([N:14]2[C:26](=[O:28])[C:25](=[C:24]([CH3:32])[CH3:33])[O:31][C:15]2=[O:16])=[C:4]([F:20])[CH:3]=1

Participants

5

Reactant 3

HCID 7622TributylamineHCID 11033971N-[4-Chloro-5-(cyclopentyloxy)-2-fluorophenyl]carbamic acid ethyl esterHCID 15389971HCID 15389971, compound

Product 1

HCID 11714234PentoxazoneYield 46.1%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
205 °C

Procedure

Ethyl N-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)carbamate (10.0 g, 33.1 mmol), ethyl 3-ethoxy-2-hydroxy-3-methylbutanoate (9.44 g, 49.7 mmol), ferric chloride hexahydrate (90.2 mg, 0.03 mmol) and tributylamine (309.5 mg, 1.7 mmol) were introduced into a two-necked eggplant type flask (200 cc) equipped with a Dean Stark and a Dimroth condenser and heated at 205° C. (oil bath) for 10 hours with stirring. After completion of the reaction, the reaction solution was cooled to room temperature, toluene (60 mL) was added, and the reaction solution was washed with water (100 mL). The organic layer was concentrated under reduced pressure, and ethanol (35 mL) acidified with hydrochloric acid was added to the resulting oily substance to form a homogeneous solution. The solution was left to stand at room temperature. The precipitated crystals were collected by filtration, then washed with ethanol acidified with hydrochloric acid and dried to obtain 3-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)-5-isopropylidene-1,3-oxazolidine-2,4-dione as white crystals (5.40 g, yield 46.1%).

Workup

  1. customequipped with a Dean Stark
  2. customAfter completion of the reaction
  3. temperaturethe reaction solution was cooled to room temperature
  4. washthe reaction solution was washed with water (100 mL)
  5. concentrationThe organic layer was concentrated under reduced pressure, and ethanol (35 mL)
  6. additionwas added to the resulting oily substance
  7. customto form a homogeneous solution
  8. waitThe solution was left
  9. customto stand at room temperature
  10. filtrationThe precipitated crystals were collected by filtration
  11. washwashed with ethanol
  12. customdried

Sources & evidence

ORD record
ord-030ccbc6be4c42a4a670b15e94db79ac
Source dataset
uspto-grants-2000_07
Patent number
US06090946

Reaction notes

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