Реакция #2122494

Уравнение реакции

Acetyl chloride

methanol

4-hydroxy-1-methoxypiperidine-4-carbonitrile

methanol

→

4-Hydroxy-1-methoxy-piperidine-4-carboxylic acid methyl ester

Условия реакции

Обработка

1. 1
   workup.ADDITIONAfter the addition
2. 2
   ДругоеThe cooling was removed
3. 3
   Другоеthe suspension formed
4. 4
   workup.WAITwas left
5. 5
   workup.STIRRINGstirring at room temperature overnight
6. 6
   ДругоеThe solvent was evaporated under vacuum
7. 7
   workup.DISSOLUTIONthe residue was dissolved in cold (0° C.) water
8. 8
   workup.ADDITIONNaHCO3 (saturated aqueous solution) was added carefully
9. 9
   ЭкстракцияThe aqueous phase was thoroughly extracted three times with ethyl acetate
10. 10
    Сушкаdried over magnesium sulfate
11. 11
    Фильтрацияfiltered
12. 12
    Концентрированиеconcentrated
13. 13
    ДругоеThe crude product was used without further purification

Методика

Acetyl chloride (40.7 g, 0.52 mol) was added slowly to dry methanol (115 ml) cooled to 0° C. under argon. After the addition, the solution was stirred for an additional ½ hour at 0° C. This solution was then added dropwise into a cold (0° C.) solution of 4-hydroxy-1-methoxypiperidine-4-carbonitrile (5.40 g, 34.6 mmol) in methanol (45 ml). The cooling was removed and the suspension formed was left stirring at room temperature overnight. The solvent was evaporated under vacuum and the residue was dissolved in cold (0° C.) water. NaHCO3 (saturated aqueous solution) was added carefully to adjust the pH to 7. The aqueous phase was thoroughly extracted three times with ethyl acetate. The organic layers were combined, dried over magnesium sulfate, filtered and concentrated. The crude product was used without further purification. Yield: 4.9 g of 4-hydroxy-1-methoxy-piperidine-4-carboxylic acid methyl ester (title compound P4.4) as light yellow oil.

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