Hydrochloric Acid → Pentoxazone

HRID 2289014Notes

Reaction equation

HRID 2289014 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:18])[O:16][CH3:17])=[C:4]([F:19])[CH:3]=1.OC([C:27]([CH3:29])=[CH2:28])C(OCC)=O.Cl.[CH3:31][OH:32]>C(N(CCCC)CCCC)CCC>[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:31](=[O:32])[C:17](=[C:27]([CH3:29])[CH3:28])[O:16][C:15]2=[O:18])=[C:4]([F:19])[CH:3]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 887MethanolHCID 108555893-Butenoic acid, 2-hydroxy-3-methyl-, ethyl esterHCID 15766845methyl N-(2-fluoro-4-chloro-5-cyclopentyloxyphenyl)carbamate

Product 1

HCID 11714234PentoxazoneYield 54.5%

Reagents, catalysts & solvents 1

HCID 7622TributylamineCatalyst

Conditions

Temperature
75 °C

Procedure

Methyl N-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)carbamate (2.87 g, 10 mmol), ethyl 2-hydroxy-3-methyl-3-butenoate (4.32 g, 30 mmol), ferric chloride (162 mg, 1.0 mmol) and tributylamine (92.7 mg, 0.5 mmol) were introduced into a flask (25 cc) equipped with a distillation unit, and the reaction was conducted at 200° C. for 3 hours. After completion of the reaction, the reaction solution was allowed to cool to 70 to 80° C., and a mixed solution consisting of methanol (5 mL) and 6N hydrochloric acid (0.25 mL) was added thereto and mixed homogeneously. Then, the reaction solution was left to stand at room temperature. The precipitated solid was collected by filtration, washed with a mixed solution consisting of methanol (8 mL) and 6N hydrochloric acid (0.8 mL) and then water (10 mL) and dried completely under reduced pressure to obtain 3-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)-5-isopropylidene-1,3-oxazolidine-2,4-dione (1.93 g, yield 54.5%).

Workup

  1. customequipped with a distillation unit
  2. customAfter completion of the reaction
  3. additionwas added
  4. additionmixed homogeneously
  5. waitThen, the reaction solution was left
  6. customto stand at room temperature
  7. filtrationThe precipitated solid was collected by filtration
  8. washwashed with a mixed solution
  9. dry with materialwater (10 mL) and dried completely under reduced pressure

Sources & evidence

ORD record
ord-ab997b7e954d4dacbfb0abb4b4861f3f
Source dataset
uspto-grants-2000_07
Patent number
US06090946

Reaction notes

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