Lawesson's reagent → tert-Butyl (S)-5-thioxo-2-pyrrolidinecarboxylate

HRID 10952

Reaction equation

HRID 10952 reaction equation
O=[C:2]1[NH:6][C@H:5]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:4][CH2:3]1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:23])=CC=1>C1C=CC=CC=1>[S:23]=[C:2]1[NH:6][C@H:5]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:4][CH2:3]1

Participants

4

Reactant 2

HCID 87949Lawesson's reagentHCID 10888648tert-Butyl 5-oxo-L-prolinate

Product 1

HCID 14416882tert-Butyl (S)-5-thioxo-2-pyrrolidinecarboxylateYield 191.1%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

To a solution of t-butyl pyroglutamate (1a) (10.12 g, 54.6 mmol) in benzene (250 mL), was added Lawesson's reagent (11.05 g, 27.3 mmol). The mixture was stirred at reflux for 15.5 h, then concentrated. The resultant residue was purified by flash chromatography (0 to 2 to 3 to 4% MeOH/CHCl3) to afford 10.50 g (95%) of the title compound, 1b. 1H NMR (300 MHz, CDCl3) δ 7.27 (br s, 1H), 4.46–4.39 (m, 1H), 3.03–2.84 (m, 2H), 2.58–2.46 (m, 1H), 2.37–2.23 (m, 2H), 1.49 (s, 9H).

Workup

  1. temperatureat reflux for 15.5 h
  2. concentrationconcentrated
  3. customThe resultant residue was purified by flash chromatography (0 to 2 to 3 to 4% MeOH/CHCl3)

Sources & evidence

ORD record
ord-585925510a744f649fc62878129472d8
Source dataset
uspto-grants-2006_08
Patent number
US07094783B2

Linked notes

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