2-(4-Chlorophenethoxy)-3-methoxypyrazine → 3-(4-chlorophenethoxy)pyrazin-2(1H)-one

HRID 906233Notes

Reaction equation

HRID 906233 reaction equation
S1C2C=CC=CC=2N=C1S.[Cl:11][C:12]1[CH:28]=[CH:27][C:15]([CH2:16][CH2:17][O:18][C:19]2[C:24]([O:25]C)=[N:23][CH:22]=[CH:21][N:20]=2)=[CH:14][CH:13]=1>CC(N(C)C)=O.C([O-])(O)=O.[Na+]>[Cl:11][C:12]1[CH:13]=[CH:14][C:15]([CH2:16][CH2:17][O:18][C:19]2[C:24](=[O:25])[NH:23][CH:22]=[CH:21][N:20]=2)=[CH:27][CH:28]=1

Participants

5

Reactant 2

HCID 575406932-(4-Chlorophenethoxy)-3-methoxypyrazineHCID 178418395HCID 178418395, compound

Product 1

HCID 580924053-(4-chlorophenethoxy)pyrazin-2(1H)-oneYield 47.9%

Reagents, catalysts & solvents 2

HCID 31374DimethylacetamideSolventHCID 516892Sodium BicarbonateSolvent2×

Conditions

Temperature
135 °C

Procedure

A mixture of benzo[d]thiazole-2-thiol (1.264 g, 7.56 mmol), 2-(4-chlorophenethoxy)-3-methoxypyrazine (1.00 g, 3.78 mmol) and NaHCO3 (1.587 g, 18.89 mmol) in DMA (10 mL) was stirred at 135° C. for 6 hours. After cooling to RT, the mixture was diluted with a solution of saturated NaHCO3 (55 ml) and was then extracted with EtOAc (60 ml). The EtOAc layer was dried over Na2SO4 and concentrated. The crude product was purified by silica gel chromatography employing a solvent gradient (hexane to 100% EtOAc) to elute 3-(4-chlorophenethoxy)pyrazin-2(1H)-one (477 mg, 1.808 mmol, 47.9% yield) as off-white solid. 1H NMR (400 MHz, chloroform-d) δ ppm 7.27-7.31 (2H, m), 7.19-7.25 (2H, m), 6.95 (1H, d, J=4.27 Hz), 6.89 (1H, d, J=4.52 Hz), 4.54 (2H, t, J=7.53 Hz), 3.14 (2H, t, J=7.40 Hz).

Workup

  1. temperatureAfter cooling to RT
  2. extractionwas then extracted with EtOAc (60 ml)
  3. dry with materialThe EtOAc layer was dried over Na2SO4
  4. concentrationconcentrated
  5. customThe crude product was purified by silica gel chromatography

Sources & evidence

ORD record
ord-d3bd87f326c5436c834c83ab687f4d84
Source dataset
uspto-grants-2011_09
Patent number
US08012984B2

Reaction notes

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