Dimethylformamide → ethyl (4S)-6-cyano-2-ethyl-8-methoxy-4-methyl-1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazin-7-carboxylate

HRID 494136Notes

Reaction equation

HRID 494136 reaction equation
Br[C:2]1[N:6]2[C@@H:7]([CH3:14])[CH2:8][N:9]([CH2:12][CH3:13])[C:10](=[O:11])[C:5]2=[C:4]([O:15][CH3:16])[C:3]=1[C:17]([O:19][CH2:20][CH3:21])=[O:18].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[CH3:41][N:42](C=O)C>[Zn].[C-]#N.[Zn+2].[C-]#N.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd]>[C:41]([C:2]1[N:6]2[C@@H:7]([CH3:14])[CH2:8][N:9]([CH2:12][CH3:13])[C:10](=[O:11])[C:5]2=[C:4]([O:15][CH3:16])[C:3]=1[C:17]([O:19][CH2:20][CH3:21])=[O:18])#[N:42]

Participants

7

Reactant 3

HCID 6228DimethylformamideHCID 11776TriphenylphosphineHCID 86624798(S)-Ethyl 6-bromo-2-ethyl-8-methoxy-4-methyl-1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-7-carboxylate

Product 1

HCID 86624801ethyl (4S)-6-cyano-2-ethyl-8-methoxy-4-methyl-1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazin-7-carboxylate

Reagents, catalysts & solvents 3

HCID 11186Zinc cyanide (Zn(CN)2)CatalystHCID 23994ZincCatalystHCID 9811564Bis(dibenzylideneacetone)palladiumCatalyst

Conditions

Temperature
140 °C

Procedure

To a mixture of ethyl (4S)-6-bromo-2-ethyl-8-methoxy-4-methyl-1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazin-7-carboxylate (4.1 g, 11.41 mmol; Example 62, step 7), zinc dust (0.15 g, 2.28 mmol), zinc cyanide (1.11 g, 9.47 mmol), triphenylphosphine (0.46 g, 1.77 mmol), and tris(dibenzylideneacetone)dipalladium (0) (1.57 g, 1.71 mmol) in anhydrous DMF (10 mL) was purged with argon gas for 15 minutes. The mixture was heated in a sealed tube in an oil bath at 140° C. overnight. The reaction mixture was filtered through a pad of Celite, and the filtrate concentrated under vacuum. The residue was partitioned between chloroform and aqueous EDTA monosodium salt. The mixture was stirred at room temperature for 30 minutes. The organic extract was washed with brine, dried over anhydrous magnesium sulfate, filtered, and concentrated under vacuum. The residue was subjected to column chromatography on silica gel eluted with 0 to 40% ethyl acetate in chloroform gradient. Collection and concentration of appropriate fractions provided the title nitrile.

Workup

  1. customwas purged with argon gas for 15 minutes
  2. filtrationThe reaction mixture was filtered through a pad of Celite
  3. concentrationthe filtrate concentrated under vacuum
  4. customThe residue was partitioned between chloroform and aqueous EDTA monosodium salt
  5. extractionThe organic extract
  6. washwas washed with brine
  7. dry with materialdried over anhydrous magnesium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated under vacuum
  10. washeluted with 0 to 40% ethyl acetate in chloroform gradient
  11. customCollection and concentration of appropriate fractions

Sources & evidence

ORD record
ord-18708559f83344628014bb586263e8d6
Source dataset
uspto-grants-2009_05
Patent number
US07538112B2

Reaction notes

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