Hydrochloric Acid → Pentoxazone

HRID 2289017Notes

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:19])[O:16][CH2:17][CH3:18])=[C:4]([F:20])[CH:3]=1.O[CH:22]([C:28](C)=C)[C:23](OCC)=O.Cl.C[OH:33]>[Cl-].C([N+](CCCC)(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:18](=[O:33])[C:17](=[C:22]([CH3:28])[CH3:23])[O:16][C:15]2=[O:19])=[C:4]([F:20])[CH:3]=1

Participants

Conditions

Temperature: 75 °C

Procedure

Ethyl N-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)carbamate (3.01 g, 10 mmol), ethyl 2-hydroxy-3-methyl-3-butenoate (2.16 g, 15 mmol) and tetrabutylammonium chloride (278 mg, 1.0 mmol) were introduced into a flask (25 cc) equipped with a distillation unit, and the reaction was conducted at 200° C. for 1.5 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 (0.4 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 (1.30 9, yield 36.7%).

Workup

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

Sources & evidence

ORD record: ord-8f4794e82eff4ba790cd525a3b3ca7aa
Source dataset: uspto-grants-2000_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06090946

Reaction notes

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