Methanol → Methyl 5-aminoisoquinoline-3-carboxylate

HRID 1902549Notes

Reaction equation

HRID 1902549 reaction equation
[NH2:1][C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[CH:4]=[C:5]([C:12]([OH:14])=[O:13])[N:6]=[CH:7]2.[CH3:15]O>>[NH2:1][C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[CH:4]=[C:5]([C:12]([O:14][CH3:15])=[O:13])[N:6]=[CH:7]2

Participants

3

Reactant 2

HCID 887MethanolHCID 205156525-Aminoisoquinoline-3-carboxylic acid

Product 1

HCID 22032628Methyl 5-aminoisoquinoline-3-carboxylate

Procedure

5-Aminoisoquinoline-3-carboxylic acid (25 g) is added to methanol (2 liters). The mixture is heated to the reflux temperature and a stream of dry hydrogen chloride is bubbled through for 3 hours. The mixture is heated under reflux for a further 3 hours and then concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 60° C. The residue is dissolved in water (200 cc) and the solution is washed with ethyl acetate (2×100 cc). The aqueous solution is rendered alkaline to pH 9 by adding potassium carbonate. The precipitate formed is filtered off, washed with water and dried to yield 5-amino-3-methoxycarbonylisoquinoline (20.3 g).

Workup

  1. temperatureThe mixture is heated to the reflux temperature
  2. customa stream of dry hydrogen chloride is bubbled through for 3 hours
  3. temperatureThe mixture is heated
  4. temperatureunder reflux for a further 3 hours
  5. concentrationconcentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 60° C
  6. dissolutionThe residue is dissolved in water (200 cc)
  7. washthe solution is washed with ethyl acetate (2×100 cc)
  8. additionby adding potassium carbonate
  9. customThe precipitate formed
  10. filtrationis filtered off
  11. washwashed with water
  12. customdried

Sources & evidence

ORD record
ord-5740640249644f00942d115b479bab0a
Source dataset
uspto-grants-1982_12
Patent number
US04363909

Reaction notes

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