Sodium hydride → Tert-butyl 2-(2-methoxyethyl)-1,3-dithiane-2-carboxylate

Temperature

0 °C

Under a nitrogen atmosphere, 60% sodium hydride (705 mg, 16.2 mmol) was suspended in anhydrous toluene (21 mL), and the suspension was cooled to 0° C. in an ice bath. In a different flask, tert-butyl 1,3-dithiane-2-carboxylate (3.235 g, 14.7 mmol) and 1-bromo-2-methoxyethane (1.52 mL, 16.15 mmol) were dissolved in N,N-dimethylformamide (7.0 mL), and the solution was added dropwise to the first flask over 15 minutes. After completion of the dropwise addition, the mixture was stirred at the same temperature for 5 minutes, and successively at room temperature for further 2 hours. The progress of the reaction was stopped by adding a saturated aqueous solution of ammonium chloride. The mixture was extracted with a mixture (1:1 v/v) of n-hexane and ethyl acetate. The separated organic layer was washed twice with water, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated. The residue was purified by silica gel column chromatography (n-hexane/ethyl acetate) to obtain the target compound at a yield of 90% (GC m/z 278 (M+); Rt 5.3 min.).

1. additionthe solution was added dropwise to the first flask over 15 minutes
2. additionAfter completion of the dropwise addition
3. waitsuccessively at room temperature for further 2 hours
4. extractionThe mixture was extracted with a mixture (1:1 v/v) of n-hexane and ethyl acetate
5. washThe separated organic layer was washed twice with water
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationThe filtrate was concentrated
9. customThe residue was purified by silica gel column chromatography (n-hexane/ethyl acetate)
10. customto obtain the target compound at a yield of 90% (GC m/z 278 (M+); Rt 5.3 min.)

ORD record

ord-646827b17b714965bc4b0d8f3ec13604

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09266853B2