Triethylamine → Pentoxazone

HRID 1198785Notes

Reaction equation

HRID 1198785 reaction equation
C(N(CC)CC)C.[F:8][C:9]1[CH:14]=[C:13]([Cl:15])[C:12]([O:16][CH:17]2[CH2:21][CH2:20][CH2:19][CH2:18]2)=[CH:11][C:10]=1[N:22]=[C:23]=[O:24].[OH:25][CH:26]([C:31]([CH3:33])=[CH2:32])[C:27]([O:29]C)=O.C(=O)([O-])[O-].[K+].[K+]>C1(C)C=CC=CC=1>[F:8][C:9]1[CH:14]=[C:13]([Cl:15])[C:12]([O:16][CH:17]2[CH2:21][CH2:20][CH2:19][CH2:18]2)=[CH:11][C:10]=1[N:22]1[C:27](=[O:29])[C:26](=[C:31]([CH3:33])[CH3:32])[O:25][C:23]1=[O:24]

Participants

6

Reactant 4

HCID 8471TriethylamineHCID 11430Potassium CarbonateHCID 13461762Methyl 2-hydroxy-3-methylbut-3-enoateHCID 544415444-Chloro-5-cyclopentyloxy-2-fluorophenylisocyanate

Product 1

HCID 11714234PentoxazoneYield 75.7%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
100 °C

Procedure

Triethylamine (40 ml) was gradually dropwise added to a toluene solution (10 liters) containing 2-fluoro-4-chloro-5-cyclopentyloxyphenylisocyanate (4.0 kg, 15.6 mol) and methyl 2-hydroxy-3-methyl-3-butenoate (2.4 kg, purity about 90 %, 18.4 mol), as put in a 20-liter stainless steel vessel, with cooling in an ice-water bath, in such a way that the temperature of the reaction solution did not rise. The whole was stirred for 2 hours at the determined temperature until the starting materials disappeared by TLC. Next, after addition of potassium carbonate (200 g, 1.45 mol), the reaction mixture was heated in a water bath (100° C.) for 4 hours with stirring with removing the methanol formed therefrom through a distillation device equipped to the reactor. After reaction, the reaction mixture was washed with 1 N hydrochloric acid (10 liters) and 1 N sodium hydroxide (10 liters) and further with 1 N hydrochloric acid (10 liters). The toluene layer was dried over anhydrous magnesium sulfate, the solvent was removed by distillation under reduced pressure, and hexane of about a half of the oily product formed was added to the oily product formed. This was then allowed to stand at room temperature for a while. A whitish yellow solid precipitated out, which was taken out by filtration and well dried to obtain 3N-(2-fluoro-4-chloro-5-cyclopentyloxyphenyl)-5-isopropylidene-1,3-oxazolidine-2, 4-dione (4.19 kg, 11.8 mol). Yield: 75.7 %. Spectral data and other data of the product are those as shown in Example 27.

Workup

  1. customas put in a 20-liter stainless steel vessel
  2. temperaturewith cooling in an ice-water bath
  3. stirringwith stirring
  4. customwith removing the methanol
  5. customformed
  6. customthrough a distillation device equipped to the reactor
  7. customAfter reaction
  8. washthe reaction mixture was washed with 1 N hydrochloric acid (10 liters) and 1 N sodium hydroxide (10 liters) and further with 1 N hydrochloric acid (10 liters)
  9. dry with materialThe toluene layer was dried over anhydrous magnesium sulfate
  10. customthe solvent was removed by distillation under reduced pressure, and hexane of about a half of the oily product
  11. customformed
  12. additionwas added to the oily product
  13. customformed
  14. customto stand at room temperature for a while
  15. customA whitish yellow solid precipitated out
  16. filtrationwhich was taken out by filtration
  17. customwell dried

Sources & evidence

ORD record
ord-35c80cfe305043579a14e346f4362a5c
Source dataset
uspto-grants-1994_01
Patent number
US05281742

Reaction notes

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