N-[2-(3,4-dimethoxyphenyl)ethyl]formamide → 3,4-Dihydro-6,7-dimethoxyisoquinoline

HRID 2118504

Reaction equation

HRID 2118504 reaction equation
[CH:1]([NH:3][CH2:4][CH2:5][C:6]1[CH:11]=[CH:10][C:9]([O:12][CH3:13])=[C:8]([O:14][CH3:15])[CH:7]=1)=O>N>[CH3:15][O:14][C:8]1[CH:7]=[C:6]2[C:11](=[CH:10][C:9]=1[O:12][CH3:13])[CH:1]=[N:3][CH2:4][CH2:5]2

Participants

3

Reactant 1

HCID 84337N-[2-(3,4-dimethoxyphenyl)ethyl]formamide

Product 1

HCID 300583,4-Dihydro-6,7-dimethoxyisoquinoline

Reagents, catalysts & solvents 1

HCID 222AmmoniaSolvent

Conditions

Temperature
140 °C

Procedure

The N-formyl-2(3,4-dimethoxy-phenyl)-ethylamine so obtained is stirred with polyphosphoric acid (1 kg) and heated to 140° C. (oil bath temperature). The reaction mixture foams vigorously starting from an internal temperature of 70° C. After 30 minutes, an internal temperature of about 140° C. is attained. The mixture is then poured onto water (1 liter) and made alkaline with concentrated ammonia (1.8 liters) while ice is added. The reaction product is extracted repeatedly with ethyl acetate, the ethyl acetate phase is washed with water, dried, over magnesium sulphate and evaporated giving the title compound (142.5 g) as an oil.

Workup

  1. customvigorously starting from an internal temperature of 70° C
  2. customan internal temperature of about 140° C.
  3. additionThe mixture is then poured onto water (1 liter)
  4. additionis added
  5. extractionThe reaction product is extracted repeatedly with ethyl acetate
  6. washthe ethyl acetate phase is washed with water
  7. dry with materialdried, over magnesium sulphate
  8. customevaporated

Sources & evidence

ORD record
ord-6d8dbedc0f774882852ce542ea9e0af5
Source dataset
uspto-grants-1987_07
Patent number
US04678792

Linked notes

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