反应详情

A solution of DMSO (1.41 mL, 19.9 mmol) in CH2Cl2 (5 mL) was added to a solution of oxalyl chloride (0.87 mL, 9.9 mmol) in CH2Cl2 (25 mL) at −60° C. After 5 min, a solution of 1-benzyl 4-tert-butyl 2-(hydroxymethyl)piperazine-1,4-dicarboxylate (3.16 g, 9.03 mmol) in CH2Cl2 (5 mL) was added. After 15 min., triethylamine (6.3 mL, 45 mmol) was added, and the reaction mixture was allowed to warm to rt. After 1 h, water (100 mL) was added, the organics were separated, and the aqueous layer was extracted with CH2Cl2 (3×100 mL). The combined organics were washed with brine (3×150 mL), 1% HCl (3×150 mL), water (150 mL), and 5% NaHCO3 (3×150 mL). The organics were dried over Na2SO4, filtered, and concentrated under reduced pressure. This gave 3.07 g (98%) of the desired product as a thick oil. Rf=0.10 in 30% EtOAc/Hexane.

1. waitAfter 15 min.
2. waitAfter 1 h
3. customthe organics were separated
4. extractionthe aqueous layer was extracted with CH2Cl2 (3×100 mL)
5. washThe combined organics were washed with brine (3×150 mL), 1% HCl (3×150 mL), water (150 mL), and 5% NaHCO3 (3×150 mL)
6. dry with materialThe organics were dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure