Trifluoromethanesulfonic acid, lithium salt → methyl (2R)-3-[(4-fluoro-3-methyl-2-oxo-2,3-dihydro-6-benzoxazolyl)amino]-2-hydroxypropanoate

HRID 723926Notes

Reaction equation

HRID 723926 reaction equation
[NH2:1][C:2]1[CH:12]=[C:11]([F:13])[C:5]2[N:6]([CH3:10])[C:7](=[O:9])[O:8][C:4]=2[CH:3]=1.[CH3:14][O:15][C:16]([C@@H:18]1[O:20][CH2:19]1)=[O:17].FC(F)(F)S([O-])(=O)=O.[Li+]>C(#N)C>[F:13][C:11]1[C:5]2[N:6]([CH3:10])[C:7](=[O:9])[O:8][C:4]=2[CH:3]=[C:2]([NH:1][CH2:19][C@@H:18]([OH:20])[C:16]([O:15][CH3:14])=[O:17])[CH:12]=1

Participants

5

Reactant 3

HCID 3664839Trifluoromethanesulfonic acid, lithium saltHCID 9877347Methyl (2R)-2-oxiranecarboxylateHCID 684860356-amino-4-fluoro-3-methyl-1,3-benzoxazol-2(3H)-one

Product 1

HCID 86610080methyl (2R)-3-[(4-fluoro-3-methyl-2-oxo-2,3-dihydro-6-benzoxazolyl)amino]-2-hydroxypropanoateYield 99.6%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Conditions

Temperature
90 °C

Procedure

A mixture of 6-amino-4-fluoro-3-methyl-1,3-benzoxazol-2(3H)-one (Step 7, 0.630 g, 3.46 mmol), methyl (2R)-glycidate (0.353 g, 3.46 mmol) and lithium trifluoromethanesulfonate (0.540 g, 3.46 mmol) in acetonitrile (10 ml) is stirred and heated at 90° C. overnight. The reaction mixture is diluted with ethyl actetate, washed with water and saline, dried (MgSO4), and evaporated under reduced pressure. Final purification by flash column chromatography (50% ethyl acetate/hexane) gives pure product as a white solid (0.98 g, 60%); MS for C12H13FN2O5 m/z 285 (M+H)+.

Workup

  1. additionThe reaction mixture is diluted with ethyl actetate
  2. washwashed with water and saline
  3. dry with materialdried (MgSO4)
  4. customevaporated under reduced pressure
  5. customFinal purification by flash column chromatography (50% ethyl acetate/hexane)

Sources & evidence

ORD record
ord-ef6eff76f4ce4ee6b98b1fc50c0c5592
Source dataset
uspto-grants-2006_11
Patent number
US07141588B2

Reaction notes

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