Реакция #50796

Уравнение реакции

1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone

1-(carboethoxy)-1-(4-methoxybenzylthio)methane

1-iodo-5-chloropentane

lithium hexamethyldisilazane

lithium hexamethyldisilazane

→

1-(carboethoxy)-1-(4-methoxybenzylthio)cyclohexane

Выход 56.6%

Растворители

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

Условия реакции

Обработка

1. 1
   workup.ADDITIONAdd, by cannula transfer
2. 2
   workup.STIRRINGStir for 1 hour
3. 3
   workup.STIRRINGStir at 0° C. for 4 hours and at room temperature for 6 hours
4. 4
   workup.STIRRINGstir at room temperature overnight
5. 5
   ДругоеQuench with saturated ammonium chloride (5 mL)
6. 6
   Другоеpartition between ethyl acetate (50 mL) and water (50 mL)
7. 7
   ДругоеSeparate the organic phase
8. 8
   Сушкаdry (Na2SO4)
9. 9
   Другоеevaporate the solvent in vacuo
10. 10
    ДругоеPurify by chromatography (6:1 hexane/ethyl acetate)

Методика

Cool lithium hexamethyldisilazane (8.4 mL of a 1.0M solution in tetrahydrofuran, 8.4 mmol) to -78° C. Add, by cannula transfer, a solution of 1-(carboethoxy)-1-(4-methoxybenzylthio)methane (2.0 g, 8.3 mmol) in tetrahydrofuran (8 mL). Stir for 45 minutes then add a solution of 1-iodo-5-chloropentane (1.94 g, 8.32 mmol) i n tetrahydrofuran (8 mL). Stir for 1 hour and add 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU) (1.21 mL, 10.0 mmol). Stir at 0° C. for 4 hours and at room temperature for 6 hours. Cool to -78° C., add lithium hexamethyldisilazane (8.4 mL, 8.4 mmol) and stir at room temperature overnight. Quench with saturated ammonium chloride (5 mL) and partition between ethyl acetate (50 mL) and water (50 mL). Separate the organic phase, dry (Na2SO4) and evaporate the solvent in vacuo. Purify by chromatography (6:1 hexane/ethyl acetate) to give 1-(carboethoxy)-1-(4-methoxybenzylthio)cyclohexane as an colorless oil (1.45 g, 56%).

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