2(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl- → 1-(Carboethoxy)-1-(4-methoxybenzylthio)cyclohexane

Temperature

-78 °C

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) in 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%).

1. additionAdd, by cannula transfer
2. stirringStir for 1 hour
3. stirringStir at 0° C. for 4 hours and at room temperature for 6 hours
4. stirringstir at room temperature overnight
5. customQuench with saturated ammonium chloride (5 mL)
6. custompartition between ethyl acetate (50 mL) and water (50 mL)
7. customSeparate the organic phase
8. dry with materialdry (Na2SO4)
9. customevaporate the solvent in vacuo
10. customPurify by chromatography (6:1 hexane/ethyl acetate)

ORD record

ord-be75b6e3c31c4b169e917fe29e3a3ac3

Source dataset

uspto-grants-1996_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05529996