Methyl cyanoacetate → 2-Methoxy-4-imino-6-oxo-dihydropyridine

HRID 355310Notes

Reaction equation

HRID 355310 reaction equation
[CH3:1][O:2][C:3]([NH2:5])=N.Cl.C[O:8][C:9](=O)[CH2:10][C:11]#[N:12].[CH3:14][O-].[Na+]>CO>[CH3:1][O:2][CH:3]1[CH2:14][C:11](=[NH:12])[CH2:10][C:9](=[O:8])[NH:5]1

Participants

5

Reactant 3

HCID 7747Methyl cyanoacetateHCID 3083899Carbamimidic acid, methyl ester, hydrochloride (1:1)HCID 10942334Sodium Methoxide

Product 1

HCID 189417882-Methoxy-4-imino-6-oxo-dihydropyridineYield 76%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Compound III is synthesized according to the procedure of Pfeiderer (Pfeilderer, W. (1957) Chem. Ber., 90:2272-2276) as follows. 12.2 g of o-methylisourea hydrochloride (110.6 mmol), 11.81 mL methylcyanoacetate (134 mmol), 12.45 g of sodium methoxide (230.5 mmol) and 80 mL of methanol are placed in a 250 mL round bottom flask. The suspension is stirred and refluxed for 5 hours at 68°-70° C. After cooling at room temperatute, the suspension is filtered through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL), and the NaCl on the filter is washed with methanol. The filtrate is filtered by gravity through a Whatman™ no. 1 paper in a 500 mL round bottom flask, and the solvent is evaporated under reduced pressure with a rotary evaporator at 50° C. The residue is solubilized with warm distilled water, and the product is precipitatedd by acidification to pH 3-4 with glacial acetic acid. After 2 hours (or overnight) at room temperature, the suspension is filtered under vacuum through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL). The product is washed with water, acetone, and dried. The product is recrystallized with water as the solvent and using charcoal for decolorizing (activated carbon, NoritrA<100 mesh, decolorizing). The yield is 76%.

Workup

  1. temperaturerefluxed for 5 hours at 68°-70° C
  2. temperatureAfter cooling at room temperatute
  3. filtrationthe suspension is filtered through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL)
  4. washthe NaCl on the filter is washed with methanol
  5. filtrationThe filtrate is filtered by gravity through a Whatman™ no
  6. custom1 paper in a 500 mL round bottom flask, and the solvent is evaporated under reduced pressure with a rotary evaporator at 50° C
  7. temperaturewith warm
  8. distillationdistilled water
  9. filtrationthe suspension is filtered under vacuum through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL)
  10. washThe product is washed with water, acetone
  11. customdried
  12. customThe product is recrystallized with water as the solvent

Sources & evidence

ORD record
ord-545a7bf2c0c04ac9af3cf98436eef268
Source dataset
uspto-grants-1998_11
Patent number
US05830672

Reaction notes

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