Реакция #45742

Уравнение реакции

trimethylsilyldiazomethane diethyl ether

sodium dihydrogenphosphate dihydrate

2-methyl-2-butene

sodium chlorite

sodium hydrogencarbonate

hydrochloric acid

2-Cyclopropyl-7-fluoro-6-formyl-5-methyl-1,3-benzoxazole-4-carbonitrile

→

Methyl 4-cyano-2-cyclopropyl-7-fluoro-5-methyl-1,3-benzoxazole-6-carboxylate

Растворители

water

tetrahydrofuran

ethyl acetate

tert-butanol

Условия реакции

Обработка

1. 1
   Другоеthe solvent was evaporated away under reduced pressure
2. 2
   ЭкстракцияThe aqueous layer was further extracted twice with ethyl acetate
3. 3
   Промывкаwashed with saturated brine
4. 4
   Сушкаdried over anhydrous sodium sulfate
5. 5
   ДругоеThe insoluble matter was separated by filtration
6. 6
   Другоеthe solvent was evaporated away under reduced pressure
7. 7
   workup.ADDITIONBenzene (6 ml) and methanol (2 ml) were added to it
8. 8
   workup.STIRRINGAfter stirring at room temperature for 18 hours
9. 9
   ЭкстракцияThe solution was extracted three times with ethyl acetate
10. 10
    Промывкаwashed with saturated brine
11. 11
    Сушкаdried over anhydrous sodium sulfate

Методика

2-Cyclopropyl-7-fluoro-6-formyl-5-methyl-1,3-benzoxazole-4-carbonitrile (I-182) (280 mg, 1.15 mmol) was dissolved in tert-butanol (8 ml), tetrahydrofuran (6 ml) and water (6 ml), then at 0° C., sodium dihydrogenphosphate dihydrate (268 mg, 1.72 mmol), 2-methyl-2-butene (515 μl, 4.59 mmol), then sodium chlorite (purity 80%, 389 mg, 3.44 mmol) were added. After stirring at room temperature for 6 hours, the solvent was evaporated away under reduced pressure. The residue was fractionated with ethyl acetate and aqueous 1 mol hydrochloric acid solution. The aqueous layer was further extracted twice with ethyl acetate. The organic layers were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. The insoluble matter was separated by filtration, then the solvent was evaporated away under reduced pressure. Benzene (6 ml) and methanol (2 ml) were added to it, then at 0° C., 2 M trimethylsilyldiazomethane/diethyl ether solution (1.15 ml, 2.29 mmol) was added. After stirring at room temperature for 18 hours, an aqueous saturated sodium hydrogencarbonate solution was added at 0° C. The solution was extracted three times with ethyl acetate. The organic layers were combined, washed with saturated brine, and dried over anhydrous sodium sulfate.

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