Dimethyl 2-methyl-1-(tosylamino)-5-(3-methyl-2-pyrazinyl)pyrrole-3,4-dicarboxylate → Dimethyl 2-methyl-5-(3-methyl-2-pyrazinyl)pyrrole-3,4-dicarboxylate

HRID 1721820Notes

Reaction equation

HRID 1721820 reaction equation
[CH3:1][C:2]1[N:3](NS(C2C=CC(C)=CC=2)(=O)=O)[C:4]([C:15]2[C:20]([CH3:21])=[N:19][CH:18]=[CH:17][N:16]=2)=[C:5]([C:11]([O:13][CH3:14])=[O:12])[C:6]=1[C:7]([O:9][CH3:10])=[O:8]>CO.[Ni]>[CH3:1][C:2]1[NH:3][C:4]([C:15]2[C:20]([CH3:21])=[N:19][CH:18]=[CH:17][N:16]=2)=[C:5]([C:11]([O:13][CH3:14])=[O:12])[C:6]=1[C:7]([O:9][CH3:10])=[O:8]

Participants

4

Reactant 1

HCID 20029390Dimethyl 2-methyl-1-(tosylamino)-5-(3-methyl-2-pyrazinyl)pyrrole-3,4-dicarboxylate

Product 1

HCID 20029384Dimethyl 2-methyl-5-(3-methyl-2-pyrazinyl)pyrrole-3,4-dicarboxylate

Reagents, catalysts & solvents 2

HCID 935NickelCatalystHCID 887MethanolSolvent2×

Procedure

A solution of 4.57 g of 31C in 20 ml of methanol was added to a mixture of 15 g of Raney nickel in 30 ml of methanol. The mixture was heated at reflux overnight, cooled and the methanol phase was decanted. The catalyst was washed with 100 ml of 1:1 mixture of methylene chloride and methanol. The washings were combined with the methanol phases, and the resulting mixture was stripped of the solvents. The residue was dissolved in a mixture of 20 ml of water and 100 ml methylene chloride. The mixture was acidified to pH=2 with 6N hydrochloric acid, and the solution was neutralized with solid sodium bicarbonate to pH=7. The organic phase was separated, dried (Na2SO4), and stripped of solvent, and the residue was flash chromtographed on silica gel, with a 7:3 v:v mixture of methylene chloride and ethyl acetate as solvent. The product was triturated with ether and the solid product was collected to give 31, as a white solid, m.p.: 155°-156° C.

Workup

  1. temperatureThe mixture was heated
  2. temperatureat reflux overnight
  3. temperaturecooled
  4. customthe methanol phase was decanted
  5. washThe catalyst was washed with 100 ml of 1:1 mixture of methylene chloride and methanol
  6. dissolutionThe residue was dissolved in a mixture of 20 ml of water and 100 ml methylene chloride
  7. customThe organic phase was separated
  8. dry with materialdried (Na2SO4)
  9. additionv mixture of methylene chloride and ethyl acetate as solvent
  10. customThe product was triturated with ether
  11. customthe solid product was collected

Sources & evidence

ORD record
ord-33a8612e3a924ea9868057c6c535e42a
Source dataset
uspto-grants-1989_08
Patent number
US04853027

Reaction notes

Loading…