N-[4-Chloro-5-(cyclopentyloxy)-2-fluorophenyl]carbamic acid ethyl ester → Pentoxazone

HRID 2289024Notes

Reaction equation

HRID 2289024 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.[OH:21][CH:22]([C:27](OC)([CH3:29])[CH3:28])[C:23]([O:25]C)=O>CCCCCC>[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:23](=[O:25])[C:22](=[C:27]([CH3:28])[CH3:29])[O:21][C:15]2=[O:16])=[C:4]([F:20])[CH:3]=1

Participants

4

Reactant 2

HCID 11033971N-[4-Chloro-5-(cyclopentyloxy)-2-fluorophenyl]carbamic acid ethyl esterHCID 18702308HCID 18702308, compound

Product 1

HCID 11714234PentoxazoneYield 21.3%

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Conditions

Temperature
195 °C

Procedure

Ethyl N-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)carbamate (2.00 g, 6.63 mmol), methyl 2-hydroxy-3-methoxy-3-methylbutanoate (2.69 g, 16.6 mmol) and stannous acetate (0.20 g) were introduced into a two-necked eggplant type flask (50 cc) equipped with a Dean Stark and heated at 195° C. for 3 hours with stirring. After completion of the reaction, hexane (10 mL) was added, and the insolubles were filtered off. The filtrate was concentrated under reduced pressure, and the resulting oily substance was purified through a silica gel column (benzene/hexane=1/3) to obtain 3-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)-5-isopropylidene-1,3-oxazolidine-2,4-dione as white crystals (0.50 g, yield 21.3%).

Workup

  1. customequipped with a Dean Stark
  2. additionwas added
  3. filtrationthe insolubles were filtered off
  4. concentrationThe filtrate was concentrated under reduced pressure
  5. customthe resulting oily substance was purified through a silica gel column (benzene/hexane=1/3)

Sources & evidence

ORD record
ord-245d4b3912b949ddb7f796eb450dea48
Source dataset
uspto-grants-2000_07
Patent number
US06090946

Reaction notes

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