Citric Acid → (S)-4,5-bis((isobutoxycarbonyl)amino)pentyl methanesulfonate

HRID 62555Notes

Reaction equation

[OH:1][CH2:2][CH2:3][CH2:4][C@H:5]([NH:15][C:16](=[O:22])[O:17][CH2:18][CH:19]([CH3:21])[CH3:20])[CH2:6][NH:7][C:8](=[O:14])[O:9][CH2:10][CH:11]([CH3:13])[CH3:12].C(N(CC)CC)C.[CH3:30][S:31](Cl)(=[O:33])=[O:32].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C(Cl)Cl>[CH3:30][S:31]([O:1][CH2:2][CH2:3][CH2:4][C@H:5]([NH:15][C:16]([O:17][CH2:18][CH:19]([CH3:21])[CH3:20])=[O:22])[CH2:6][NH:7][C:8]([O:9][CH2:10][CH:11]([CH3:12])[CH3:13])=[O:14])(=[O:33])=[O:32]

Participants

Conditions

Temperature: -78 °C

Procedure

A round bottom flask was charged with (S)-diisobutyl (5-hydroxypentane-1,2-diyl)dicarbamate (5.0 g, 15.7 mmol), CH2Cl2 (80 mL), and triethylamine (5.3 mL, 38 mmol), and cooled to −78° C. Methanesulfonyl chloride (2.3 mL, 30 mmol) was added dropwise with stirring and the cold bath was allowed to warm to 0° C. over the course of 5 h. Aqueous citric acid (20%, 140 mL) and CH2Cl2 (150 mL) were added and the phases were separated. The organic phase was washed with saturated NaHCO3 solution, and then dried on anhydrous Na2SO4. The solvent was removed by rotary evaporation and dried in oil pump vacuum. The product (S)-4,5-bis((isobutoxycarbonyl)amino)pentyl methanesulfonate was obtained as a yellowish white solid. The crude product was used without further purification in the next procedure.

Workup

temperatureto warm to 0° C. over the course of 5 h
customthe phases were separated
washThe organic phase was washed with saturated NaHCO3 solution
dry with materialdried on anhydrous Na2SO4
customThe solvent was removed by rotary evaporation
customdried in oil pump vacuum

Sources & evidence

ORD record: ord-87a66e7d222641ecb55e53174d3e22fc
Source dataset: uspto-grants-2016_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09446393B2

Reaction notes

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