2,2-Dimethoxypropane → 3-tert-butyl 4-methyl (4R)-2,2-dimethyl-1,3-oxazolidine-3,4-dicarboxylate

HRID 539987

Reaction equation

HRID 539987 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]([CH2:14][OH:15])[C:10]([O:12][CH3:13])=[O:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].CO[C:18](OC)([CH3:20])[CH3:19]>C1(C)C=CC=CC=1.CC1C=CC(S(O)(=O)=O)=CC=1>[CH3:19][C:18]1([CH3:20])[N:8]([C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:7])[C@@H:9]([C:10]([O:12][CH3:13])=[O:11])[CH2:14][O:15]1

Participants

5

Reactant 2

HCID 64952,2-DimethoxypropaneHCID 377723N-Boc-D-serine methyl ester

Product 1

HCID 6882203-tert-butyl 4-methyl (4R)-2,2-dimethyl-1,3-oxazolidine-3,4-dicarboxylateYield 63.6%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 1140TolueneSolvent

Conditions

Temperature
110 °C

Procedure

A solution of methyl (2R)-2-{[(tert-butoxy)carbonyl]amino}-3-hydroxypropanoate (22 g, 0.1 mol), 2,2-dimethoxypropane (20.8 g, 0.2 mol) and 4-methylbenzene-1-sulfonic acid (0.5 g) in toluene was heated with stirring at 110° C. overnight. The solvent was removed under reduced pressure. The residue was treated with ethyl acetate, washed with water and brine. The organic layer was dried over sodium sulfate, concentrated under reduced pressure. The residue distilled at 0.6 mbar to give 16.5 g of 3-tert-butyl 4-methyl (4R)-2,2-dimethyl-1,3-oxazolidine-3,4-dicarboxylate (yield was 63.6%) as an amber oil.

Workup

  1. customThe solvent was removed under reduced pressure
  2. additionThe residue was treated with ethyl acetate
  3. washwashed with water and brine
  4. dry with materialThe organic layer was dried over sodium sulfate
  5. concentrationconcentrated under reduced pressure
  6. distillationThe residue distilled at 0.6 mbar

Sources & evidence

ORD record
ord-8e23414674814296af705f34c43a7805
Source dataset
uspto-grants-2014_10
Patent number
US08871756B2

Linked notes

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