4-Chloro-3-hydroxybutyric acid ethyl ester, (3R)- → [(R)-3-(2,3-dihydro-benzo[1,4]dioxin-6-yl)-2-oxo-oxazolidin-5-yl]-acetic acid ethyl ester

HRID 1640522

Reaction equation

HRID 1640522 reaction equation
Cl[CH2:2][C@H:3]([OH:10])[CH2:4][C:5]([O:7][CH2:8][CH3:9])=[O:6].[O:11]1[C:16]2[CH:17]=[CH:18][C:19]([N:21]=[C:22]=[O:23])=[CH:20][C:15]=2[O:14][CH2:13][CH2:12]1>C1C=CC=CC=1>[CH2:8]([O:7][C:5](=[O:6])[CH2:4][C@H:3]1[O:10][C:22](=[O:23])[N:21]([C:19]2[CH:18]=[CH:17][C:16]3[O:11][CH2:12][CH2:13][O:14][C:15]=3[CH:20]=2)[CH2:2]1)[CH3:9]

Participants

4

Procedure

A solution of ethyl (R)-4-chloro-3-hydroxybutyrate (5.0 g, 30 mmol) and 2,3-dihydro-1,4-benzodioxin-6-yl isocyanate (5.3 g, 30 mmol) in benzene (150 ml) was stirred at 80° C. for 48 h. The reaction mixture was concentrated in vacuo, taken up in EA and washed twice with brine. The org. layer was dried over MgSO4 and concentrated. The residue was purified by chromatography on SiO2 (hept/EA 9:1 to 1:1) to give the desired carbamate (8.3 g, 81% yield) as a yellow oil. This intermediate was dissolved in DMF (40 ml) and treated with K2CO3 (3.3 g, 24 mmol). The heterogeneous mixture was stirred at rt for 20 h, water was added and the mixture extracted with EA. The org. layers were washed with water and brine, dried over MgSO4 and concentrated. The residue was purified by chromatography on SiO2 (Hept/EA 2:1, 1:1) to give the desired oxazolidinone (0.96 g, 13% yield) as an orange solid.

Workup

  1. concentrationThe reaction mixture was concentrated in vacuo
  2. washwashed twice with brine
  3. dry with materiallayer was dried over MgSO4
  4. concentrationconcentrated
  5. customThe residue was purified by chromatography on SiO2 (hept/EA 9:1 to 1:1)

Sources & evidence

ORD record
ord-8d71d8e8597d45999baada2d8d8c17ed
Source dataset
uspto-grants-2012_02
Patent number
US08114867B2

Linked notes

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