Sulfuric Acid → methyl 6-amino-2,3-dihydro-1H-benzo[d]pyrrolo[1,2-a]imidazole-5-carboxylate

HRID 715986Notes

Reaction equation

HRID 715986 reaction equation
CC(C)(C)C([NH:5][C:6]1[C:17]([C:18]([O:20][CH3:21])=[O:19])=[C:10]2[N:11]=[C:12]3[CH2:16][CH2:15][CH2:14][N:13]3[C:9]2=[CH:8][CH:7]=1)=O.S(=O)(=O)(O)O>CO>[NH2:5][C:6]1[C:17]([C:18]([O:20][CH3:21])=[O:19])=[C:10]2[N:11]=[C:12]3[CH2:16][CH2:15][CH2:14][N:13]3[C:9]2=[CH:8][CH:7]=1

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 70983330methyl 6-(2,2-dimethylpropionylamino)-2,3-dihydro-1H-benzo[d]pyrrolo[1,2-a]imidazole-5-carboxylate2×

Product 1

HCID 86712122methyl 6-amino-2,3-dihydro-1H-benzo[d]pyrrolo[1,2-a]imidazole-5-carboxylateYield 66.2%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of methyl 6-(2,2-dimethylpropionylamino)-2,3-dihydro-1Hbenzo[d]pyrrolo[1,2-a]imidazole-5-carboxylate (Intermediate 56, 0.61 g) and concentrated sulfuric acid (1.5 mL) in methanol (30 mL) was stirred and heated at reflux for 44 hours. After cooling, the solution was concentrated in vacuo and the residue was dissolved in water and ethyl acetate and basified with 5M sodium hydroxide solution. The aqueous phase was extracted with ethyl acetate (×8) and the combined extracts were dried (Na2SO4) and filtered. The filtrate was concentrated in vacuo and the residue was triturated with ether and filtered to give methyl 6-amino-2,3-dihydro-1H-benzo[d]pyrrolo[1,2-a]imidazole-5-carboxylate (0.296 g) as an off-white solid.

Workup

  1. temperatureheated
  2. temperatureat reflux for 44 hours
  3. temperatureAfter cooling
  4. concentrationthe solution was concentrated in vacuo
  5. dissolutionthe residue was dissolved in water
  6. extractionThe aqueous phase was extracted with ethyl acetate (×8)
  7. dry with materialthe combined extracts were dried (Na2SO4)
  8. filtrationfiltered
  9. concentrationThe filtrate was concentrated in vacuo
  10. customthe residue was triturated with ether
  11. filtrationfiltered

Sources & evidence

ORD record
ord-12b7980aee334d7991cb4dd5ba7871ec
Source dataset
uspto-grants-2015_11
Patent number
US09187494B2

Reaction notes

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