Thionyl Chloride → 1,10a-Dihydropyrrolo[1,2-b]isoquinoline-3,10[2H,5H]-dione

HRID 1252290Notes

Reaction equation

HRID 1252290 reaction equation
[CH2:1]([N:8]1[C:12](=[O:13])[CH2:11][CH2:10][C@H:9]1[C:14]([OH:16])=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O=S(Cl)Cl.[Cl-].[Al+3].[Cl-].[Cl-]>CN(C)C=O>[CH2:10]1[CH:9]2[N:8]([CH2:1][C:2]3[CH:3]=[CH:4][CH:5]=[CH:6][C:7]=3[C:14]2=[O:16])[C:12](=[O:13])[CH2:11]1

Participants

5

Reactant 3

HCID 24386Thionyl ChlorideHCID 6451240Aluminum(III) ChlorideHCID 10900113(S)-1-Benzyl-5-carboxy-2-pyrrolidinone

Product 1

HCID 131500811,10a-Dihydropyrrolo[1,2-b]isoquinoline-3,10[2H,5H]-dioneYield 69.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution prepared from 11.68 g of (+)-N-benzylpyroglutamic acid (See E. Campaigne and D. P. Matthews, J. Het. Chem., 12, 391 (1975)), 100 ml of CH2CL2 and a drop of dimethylformamide (DMF), 7.57 g of SOCl2 was added dropwise. The mixture was refluxed for five hours and allowed to stand overnight at ambient temperature. The reaction mixture was cooled in an ice-salt bath. Aluminum chloride (22.6 g) was added in portions with exclusion of moisture and vigorous stirring. The temperature did not exceed 10° C. during the addition. The mixture was stirred 1.5 hours and then ice was added gradually. The mixture was partitioned between water and CH2Cl2. The CH2Cl2 phase was washed with water, dried (Na2SO4), filtered and evaporated to give 10 g of a crude product. Recrystallization from toluene gave 7.45 g of crystals, m.p. 103°-105° C.

Workup

  1. temperatureThe mixture was refluxed for five hours
  2. temperatureThe reaction mixture was cooled in an ice-salt bath
  3. additionThe temperature did not exceed 10° C. during the addition
  4. additionice was added gradually
  5. customThe mixture was partitioned between water and CH2Cl2
  6. washThe CH2Cl2 phase was washed with water
  7. dry with materialdried (Na2SO4)
  8. filtrationfiltered
  9. customevaporated
  10. customto give 10 g of a crude product
  11. customRecrystallization from toluene

Sources & evidence

ORD record
ord-539b7b3645e54b418045a2520ce53317
Source dataset
uspto-grants-1988_05
Patent number
US04742171

Reaction notes

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