Lawesson's reagent → 2-(7-Fluoro-6-nitro-3-thioxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester

HRID 518974Notes

Reaction equation

HRID 518974 reaction equation
[CH2:1]([O:3][C:4](=[O:22])[CH:5]([N:7]1[C:12]2[CH:13]=[C:14]([N+:18]([O-:20])=[O:19])[C:15]([F:17])=[CH:16][C:11]=2[O:10][CH2:9][C:8]1=O)[CH3:6])[CH3:2].COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:32])=CC=1>C1(C)C=CC=CC=1>[CH2:1]([O:3][C:4](=[O:22])[CH:5]([N:7]1[C:12]2[CH:13]=[C:14]([N+:18]([O-:20])=[O:19])[C:15]([F:17])=[CH:16][C:11]=2[O:10][CH2:9][C:8]1=[S:32])[CH3:6])[CH3:2]

Participants

4

Reactant 2

HCID 87949Lawesson's reagentHCID 867273232-(7-Fluoro-6-nitro-3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester

Product 1

HCID 867273242-(7-Fluoro-6-nitro-3-thioxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl esterYield 85.3%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A suspension of 2-(7-fluoro-6-nitro-3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester (1.170 g, 3.75 mmol) and Lawesson's reagent (1.516 g, 3.75 mmol) in toluene (40 mL) was heated at reflux for 3 h then cooled to ambient temperature. The reaction mixture was filtered and the filtrate was concentrated in vacuo. The residue was purified by column on silica gel (eluting with 0%˜10% EtOAc in petroleum ether) to give 2-(7-fluoro-6-nitro-3-thioxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propionic acid ethyl ester as a light yellow solid (1.05 g, 85%). 1H NMR (DMSO-d6, 400 MHz): δ 7.86 (d, J=6.8 Hz, 1H), 7.43 (d, J=11.6 Hz, 1H), 6.16 (brs, 1H), 5.07 (s, 2H), 4.02-4.10 (q, J=7.2 Hz, 2H), 1.58 (d, J=6.8 Hz, 3H), 1.04 (t, J=7.2 Hz, 3H).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 3 h
  3. filtrationThe reaction mixture was filtered
  4. concentrationthe filtrate was concentrated in vacuo
  5. customThe residue was purified by column on silica gel (eluting with 0%˜10% EtOAc in petroleum ether)

Sources & evidence

ORD record
ord-3e7924d5b50249389d34abec12a11ef9
Source dataset
uspto-grants-2015_08
Patent number
US09115151B2

Reaction notes

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