Dabco → Methyl 6-(3,3-diethoxyprop-1-ynyl)-5-methyl-3-oxo-4-(3-(trifluoromethyl)phenyl)-3,4-dihydropyrazine-2-carboxylate

HRID 1259329Notes

Reaction equation

HRID 1259329 reaction equation
I[C:2]1[N:7]=[C:6]([C:8]([O:10][CH3:11])=[O:9])[C:5](=[O:12])[N:4]([C:13]2[CH:18]=[CH:17][CH:16]=[C:15]([C:19]([F:22])([F:21])[F:20])[CH:14]=2)[C:3]=1[CH3:23].C(P(C(C)(C)C)C(C)(C)C)(C)(C)C.[CH2:37]([O:39][CH:40]([O:43][CH2:44][CH3:45])[C:41]#[CH:42])[CH3:38].N12CCN(CC1)CC2>CCCCCC.CN(C=O)C.[CH2-]C=C.[CH2-]C=C.Cl[Pd+].Cl[Pd+]>[CH2:37]([O:39][CH:40]([O:43][CH2:44][CH3:45])[C:41]#[C:42][C:2]1[N:7]=[C:6]([C:8]([O:10][CH3:11])=[O:9])[C:5](=[O:12])[N:4]([C:13]2[CH:18]=[CH:17][CH:16]=[C:15]([C:19]([F:22])([F:21])[F:20])[CH:14]=2)[C:3]=1[CH3:23])[CH3:38]

Participants

8

Reactant 4

HCID 9237DabcoHCID 662853,3-DiethoxypropyneHCID 83681Tris(1,1-dimethylethyl)phosphineHCID 66738777Methyl 6-iodo-5-methyl-3-oxo-4-[3-(trifluoromethyl)phenyl]-3,4-dihydropyrazine-2-carboxylate

Product 1

HCID 59564940Methyl 6-(3,3-diethoxyprop-1-ynyl)-5-methyl-3-oxo-4-(3-(trifluoromethyl)phenyl)-3,4-dihydropyrazine-2-carboxylateYield 37.5%

Reagents, catalysts & solvents 3

HCID 61538Palladium, di-mu-chlorobis(eta3-2-propenyl)di-CatalystHCID 6228DimethylformamideSolvent2×HCID 8058HexaneSolvent

Procedure

Methyl 6-iodo-5-methyl-3-oxo-4-[3-(trifluoromethyl)phenyl]-3,4-dihydropyrazine-2-carboxylate (SM1, 1.2 g, 2.8 mmol), allylpalladium(II) chloride dimer (0.0072 g), 10% by weight tri(tert-butyl)phosphine in hexane (2.1 mL) and anhydrous DMF (3.0 mL) were stirred until a clear solution was obtained. Propargylaldehyde diethyl acetal (0.44 mL, 3.1 mmol) in anhydrous DMF (2.3 mL) was added, followed by 1,4-diazabicyclo[2.2.2]octane (0.63 g, 5.6 mmol) in small portions. The red solution was purged with dry argon for 5 minutes and then stirred under argon at RT. After 4 h, the solvent was evaporated off using an oil pump. The residue was taken up in acetonitrile (10 mL), filtered through glass-wool and then concentrated with silica. Chromatography on silica with ethyl acetate-heptanes (1:10 and 1:2) as eluents gave the title compound (0.46 g, 37%) as a yellow oil.

Workup

  1. customwas obtained
  2. customThe red solution was purged with dry argon for 5 minutes
  3. customthe solvent was evaporated off
  4. filtrationfiltered through glass-wool
  5. concentrationconcentrated with silica

Sources & evidence

ORD record
ord-0a14f198dc2a45e7a91604b7b39627e7
Source dataset
uspto-grants-2013_06
Patent number
US08466284B2

Reaction notes

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