Toluene → HCID 178424531, compound

HRID 2121582Notes

Reaction equation

HRID 2121582 reaction equation
N[C:2]1[C:3]([C:16]2[C:21]([CH3:22])=[CH:20][C:19]([CH3:23])=[CH:18][C:17]=2[CH3:24])=[C:4]2[N:9]([C:10]=1[C:11](OCC)=O)C=C[CH:6]=[CH:5]2.C[C:26]1([CH3:39])C2(CS(O)(=O)=O)C(CC1CC2)=O.C[Si]([N-:44][Si](C)(C)C)(C)C.[K+].C1(C)C=CC=CC=1.C[O:58][C:59](OC)([CH3:61])[CH3:60]>>[CH3:39][C:26]1[CH:60]=[C:59]([OH:58])[C:61]2[N:9]3[C:4]([C:3]([C:16]4[C:17]([CH3:24])=[CH:18][C:19]([CH3:23])=[CH:20][C:21]=4[CH3:22])=[CH:2][CH:11]=[CH:10]3)=[CH:5][C:6]=2[N:44]=1

Participants

6

Reactant 5

HCID 1140TolueneHCID 64952,2-DimethoxypropaneHCID 18462Bicyclo[2.2.1]heptane-1-methanesulfonic acid, 7,7-dimethyl-2-oxo-, (1S)-HCID 3251421Potassium bis(trimethylsilyl)amideHCID 22034120HCID 22034120, compound

Product 1

HCID 178424531HCID 178424531, compound

Procedure

To a solution of 2-ethyl 2-amino-1-(2,4,6-trimethylphenyl)indolizine-3-carboxylate (19.2 g; 59.6 mmol) in 2,2-dimethoxypropane (100 mL), add dl-camphorsulfonic acid (0.2 g). Stir the mixture at reflux for 30 min and then distill slowly to remove ca. 60 mL of volatiles over a 30-minute period. Cool the solution to ambient temperature under inert atmosphere, dilute with anhydrous toluene (50 mL), and concentrate in vacuo. Dissolve the residue in toluene (50 mL) and add dropwise over a 1-hour period a 0.5 M solution of potassium bis(trimethylsilyl)amide in toluene (250 mL; 125 mmol) to the stirred solution. After the addition, stir the mixture for 2 h at ambient temperature, concentrate in vacuo to a small volume and dilute with aqueous NH4Cl. Filter the resulting biphasic mixture and wash successively with water, MeOH, and Et2O. Dry under vacuum to obtain the title compound as a pale yellow solid.

Workup

  1. temperatureat reflux for 30 min
  2. distillationdistill slowly
  3. customto remove ca. 60 mL of volatiles over a 30-minute period
  4. additiondilute with anhydrous toluene (50 mL)
  5. concentrationconcentrate in vacuo
  6. dissolutionDissolve the residue in toluene (50 mL)
  7. additionAfter the addition
  8. stirringstir the mixture for 2 h at ambient temperature
  9. concentrationconcentrate in vacuo to a small volume
  10. additiondilute with aqueous NH4Cl
  11. filtrationFilter the resulting biphasic mixture
  12. washwash successively with water, MeOH, and Et2O
  13. customDry under vacuum

Sources & evidence

ORD record
ord-390234e6433d4c578d2875cec2ae1fed
Source dataset
uspto-grants-2004_02
Patent number
US06696445B2

Reaction notes

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