Triethylamine → Pentoxazone

HRID 2225947Notes

Reaction equation

HRID 2225947 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 1N hydrochloric acid (10 liters) and 1N sodium hydroxide (10 liters) and further with 1N 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 1N hydrochloric acid (10 liters) and 1N sodium hydroxide (10 liters) and further with 1N 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-b21a4b3d76ba4171a9bb5f4e704fa61c
Source dataset
uspto-grants-1994_09
Patent number
US05344953

Reaction notes

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