Lawesson's reagent → (5R)-3-(3,4-dihydro-4-methyl-3-thioxo-2H-1,4-benzothiazin-7-yl)-2-oxo-5-oxazolidinecarboxylic acid methyl ester

HRID 1991330Notes

Reaction equation

HRID 1991330 reaction equation
[CH3:1][O:2][C:3]([C@@H:5]1[O:9][C:8](=[O:10])[N:7]([C:11]2[CH:22]=[CH:21][C:14]3[N:15]([CH3:20])[C:16](=O)[CH2:17][S:18][C:13]=3[CH:12]=2)[CH2:6]1)=[O:4].COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:32])=CC=1>O1CCOCC1>[CH3:1][O:2][C:3]([C@@H:5]1[O:9][C:8](=[O:10])[N:7]([C:11]2[CH:22]=[CH:21][C:14]3[N:15]([CH3:20])[C:16](=[S:32])[CH2:17][S:18][C:13]=3[CH:12]=2)[CH2:6]1)=[O:4]

Participants

4

Reactant 2

HCID 87949Lawesson's reagentHCID 68489755(5R)-3-(3,4-dihydro-4-methyl-3-oxo-2H-1,4-benzothiazin-7-yl)-2-oxo-5-oxazolidinecarboxylic acid methyl ester

Product 1

HCID 86591301(5R)-3-(3,4-dihydro-4-methyl-3-thioxo-2H-1,4-benzothiazin-7-yl)-2-oxo-5-oxazolidinecarboxylic acid methyl esterYield 89.2%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Conditions

Temperature
75 °C

Procedure

To a stirred suspension of the (5R)-3-(3,4-dihydro-4-methyl-3-oxo-2H-1,4-benzothiazin-7-yl)-2-oxo-5-oxazolidinecarboxylic acid methyl ester (EXAMPLE 62, Step 5, 1.26 g, 3.907 mmol) in dry dioxane (25 mL) is added Lawesson's reagent (2.37 g, 5.861 mmol). This reaction mixture is heated at 70-80° C. for 1.5-2 h at which time the reaction is cooled to room temperature and concentrated under reduced pressure. The residue is washed with EtOAc (15 mL×3), sonicated and filtered to give the title compound as a yellow solid (1.18 g, 89%), MS (m/z): 339.5 [M+H]+.

Workup

  1. temperatureis cooled to room temperature
  2. concentrationconcentrated under reduced pressure
  3. washThe residue is washed with EtOAc (15 mL×3)
  4. customsonicated
  5. filtrationfiltered

Sources & evidence

ORD record
ord-fc10d96145574116ae770a928d4bbda2
Source dataset
uspto-grants-2010_01
Patent number
US07645781B2

Reaction notes

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