Tin tetrachloride → dimethyl(2S,5R)-5-propynyl-pyrrolidine-1,2-dicarboxylate

HRID 475399Notes

Reaction equation

HRID 475399 reaction equation
CO[CH:3]1[N:7]([C:8]([O:10][CH3:11])=[O:9])[C@H:6]([C:12]([O:14][CH3:15])=[O:13])[CH2:5][CH2:4]1.C[Si]([C:20]#[C:21][CH3:22])(C)C.[Sn](Cl)(Cl)(Cl)Cl.[Cl-].[Al+3].[Cl-].[Cl-]>C(Cl)Cl>[C:20]([C@@H:3]1[N:7]([C:8]([O:10][CH3:11])=[O:9])[C@H:6]([C:12]([O:14][CH3:15])=[O:13])[CH2:5][CH2:4]1)#[C:21][CH3:22]

Participants

6

Reactant 4

HCID 24287Tin tetrachlorideHCID 803631-(Trimethylsilyl)prop-1-yneHCID 6451240Aluminum(III) ChlorideHCID 11053097Dimethyl (2S)-5-methoxypyrrolidine-1,2-dicarboxylate

Product 1

HCID 66756906dimethyl(2S,5R)-5-propynyl-pyrrolidine-1,2-dicarboxylate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a cold −45° C. solution of dimethyl(2S)-5-methoxypyrrolidine-1,2-dicarboxylate (10 g, 46.08 mmol, Example 1B) and trimethylsilylpropyne (14.24 ml, 92.16 mmol, 2.0 equiv) in methylene chloride (180 mL) was added a solution of tin (IV) chloride (1 M in methylene chloride, 60.0 mL, 60.0 mmol, 1.3 equiv) dropwise via an addition funnel over 30 minutes. To the dark yellow solution was added solid aluminum chloride (8.58 g, 64.52 mmol, 1.4 equiv) in one portion. The resulting mixture was allowed to warm to room temperature and stirred at room temperature for 48 hours. The reaction mixture was carefully quenched by saturated aqueous NH4OH (100 mL) with ice cooling. A white precipitate formed and was removed by filtration. The crude product was obtained after concentration. The residue was chromatographed on a Biotage flash 40 M eluting with 70% hexane/30% ethyl acetate to afford the titled compound. MS (DCI/NH3) m/e 226 (M+H)+.

Workup

  1. customThe reaction mixture was carefully quenched by saturated aqueous NH4OH (100 mL) with ice cooling
  2. customA white precipitate formed
  3. customwas removed by filtration
  4. customThe crude product was obtained
  5. concentrationafter concentration
  6. customThe residue was chromatographed on a Biotage flash 40 M
  7. washeluting with 70% hexane/30% ethyl acetate

Sources & evidence

ORD record
ord-ec34b8be03f4430f9899cb8f2caf7f76
Source dataset
uspto-grants-2014_01
Patent number
US08637546B2

Reaction notes

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