Methyl iodide → (S)-2-Methoxycarbonylmethyl-piperazine-1,4-dicarboxylic acid 4-benzyl ester 1-tert-butyl ester

To a solution of the compound of step 1 (2.52 g, 6.66 mmol) in 45 ml of acetone were added potassium carbonate (5.522 g, 39.96 mmol) and iodomethane (1.24 ml, 19.98 mmol) and the solution was stirred at room temperature overnight. The mixture was filtered and the filtrate was concentrated to dryness. The residue was dissolved in EA, washed twice with brine, dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by chromatography on silica gel (cyclohexane/EA, 100:0, then 85:15) to give 2.334 g of the title compound as a colorless oil.

1. filtrationThe mixture was filtered
2. concentrationthe filtrate was concentrated to dryness
3. dissolutionThe residue was dissolved in EA
4. washwashed twice with brine
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. customevaporated under reduced pressure
8. customThe residue was purified by chromatography on silica gel (cyclohexane/EA, 100:0

ORD record

ord-449a547b11ce4819919a2983f7b03f26

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08415336B2