Dimethyl Sulfoxide → 1,4-Di-tert-butyl 2-formylpiperazine-1,4-dicarboxylate

A solution of DMSO (0.54 mL, 7.66 mmol) in CH2Cl2 (1 mL) was added to a solution of oxalyl chloride (0.33 mL, 3.8 mmol) in CH2Cl2 (8 mL) at −60° C. After 5 min, a solution of di-tert-butyl 2-(hydroxymethyl)piperazine-1,4-dicarboxylate (1.10 g, 3.48 mmol) in CH2Cl2 (3 mL) was added. After 15 min, triethylamine (2.4 mL, 17 mmol) was added, and the reaction mixture was allowed to warm to rt. After 1 h, water (25 mL) was added, the organics were separated, and the aqueous layer was extracted with CH2Cl2 (3×25 mL). The combined organics were washed with brine (3×50 mL), 1% HCl (3×50 mL), water (50 mL), and 5% NaHCO3 (3×50 mL). The organics were dried over Na2SO4, filtered, and concentrated under reduced pressure. The material was purified by column chromatography (10 to 20% EtOAc in Hexanes gradient), yielding 0.873 g (80%) of the desired product as a white solid. Rf=0.70 in 50% EtOAc/Hexane.

1. waitAfter 15 min
2. waitAfter 1 h
3. customthe organics were separated
4. extractionthe aqueous layer was extracted with CH2Cl2 (3×25 mL)
5. washThe combined organics were washed with brine (3×50 mL), 1% HCl (3×50 mL), water (50 mL), and 5% NaHCO3 (3×50 mL)
6. dry with materialThe organics were dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe material was purified by column chromatography (10 to 20% EtOAc in Hexanes gradient)

ORD-Eintrag

ord-4d9638848eaf4ea4bb6a242c25d694d5

Quelldatensatz

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09428522B2