Phosphorus oxychloride → 6-Methoxy-1-methyl-3,4-dihydroisoquinoline

HRID 35236Notes

Reaction equation

HRID 35236 reaction equation
[C:1]([NH:4][CH2:5][CH2:6][C:7]1[CH:12]=[CH:11][CH:10]=[C:9]([O:13][CH3:14])[CH:8]=1)(=O)[CH3:2].P(Cl)(Cl)(Cl)=O>C1(C)C=CC=CC=1>[CH3:14][O:13][C:9]1[CH:8]=[C:7]2[C:12](=[CH:11][CH:10]=1)[C:1]([CH3:2])=[N:4][CH2:5][CH2:6]2

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 10330235N-[2-(3-methoxyphenyl)ethyl]acetamide

Product 1

HCID 138591866-Methoxy-1-methyl-3,4-dihydroisoquinolineYield 64.2%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a stirred solution of N-acetyl-3-methoxyphenethylamine (96.0 g, 0.497 m) in toluene (600 ml) at 15°-20° C. phosphorus oxychloride (190.5 g, 1.24 m) was added dropwise over 2 hours. The reaction was stirred overnight at room temperature, then poured into 1 liter of ice water. The organic layer was washed with dilute HCl (2×300 ml), and the aqueous layers were combined, basified, and extracted with CHCl3 (2×500 ml). The dried chloroform layer (MgSO4) was concentrated to an oil. The oil was dissolved in ether and acidified with HCl gas to yield 55.9 g of the product, 3,4-dihydro-6-methoxy-1-methylisoquinoline, m.p. 206°-207°.

Workup

  1. washThe organic layer was washed with dilute HCl (2×300 ml)
  2. extractionextracted with CHCl3 (2×500 ml)
  3. concentrationThe dried chloroform layer (MgSO4) was concentrated to an oil
  4. dissolutionThe oil was dissolved in ether

Sources & evidence

ORD record
ord-beb59b12eed641519081d3a076ad5d99
Source dataset
uspto-grants-1988_08
Patent number
US04766131

Reaction notes

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