2,4-Dimethylbenzylamine → 6,8-Dimethylisoquinolin-3-amine

HRID 250140Notes

Reaction equation

HRID 250140 reaction equation
C(O[CH:4](OCC)[C:5](=[NH:8])OC)C.[CH3:12][C:13]1[CH:18]=[C:17]([CH3:19])[CH:16]=[CH:15][C:14]=1[CH2:20][NH2:21]>CO>[CH3:19][C:17]1[CH:16]=[C:15]2[C:4](=[C:13]([CH3:12])[CH:18]=1)[CH:5]=[N:8][C:20]([NH2:21])=[CH:14]2

Participants

4

Reactant 2

HCID 667612,4-DimethylbenzylamineHCID 17874536Methyl 2,2-diethoxyethanecarboximidate

Product 1

HCID 574766096,8-Dimethylisoquinolin-3-amineYield 90%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
70 °C

Procedure

To a solution of methyl 2,2-diethoxyacetimidate (1.5 g, 9.3 mmol) in methanol (4.9 mL) was added (2,4-dimethylphenyl)methanamine (1.2 g, 8.9 mmol) dropwise at ambient temperature. The reaction flask was then placed into a preheated oil-bath and stirred at 70° C. for 16 h, then cooled and the volatiles removed under reduced pressure. The crude material was added dropwise to sulfuric acid (19.7 mL) at ambient temperature and stirred for 72 h. The flask was then placed into an ice-water bath, diluted with water (50 mL), and slowly neutralized to pH=10 with sodium hydroxide (10 N). As the reaction mixture became basic, an orange precipitate formed. This precipitate was filtered, washed with water, and dried to afford 6,8-dimethylisoquinolin-3-amine (1.37 g, 7.95 mmol, 90%). 1H NMR (400 MHz, MeOD) δ ppm 8.82 (s, 1H), 7.17 (s, 1H), 6.90 (s, 1H), 6.72 (s, 1H), 2.61 (s, 3H), 2.37 (s, 3H). MS (LC/MS) R.T.=0.77; [M+H]+=173.15.

Workup

  1. customThe reaction flask was then placed into a preheated oil-bath
  2. temperaturecooled
  3. customthe volatiles removed under reduced pressure
  4. additionThe crude material was added dropwise to sulfuric acid (19.7 mL) at ambient temperature
  5. stirringstirred for 72 h
  6. customThe flask was then placed into an ice-water bath
  7. additiondiluted with water (50 mL)
  8. customan orange precipitate formed
  9. filtrationThis precipitate was filtered
  10. washwashed with water
  11. customdried

Sources & evidence

ORD record
ord-ef5c9351941e43ea823dd64cd92184db
Source dataset
uspto-grants-2011_01
Patent number
US07863291B2

Reaction notes

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