Methyl p-toluenesulfonate → N-Methyl 3,4-dihydroisoquinolinium p-toluene sulfonate

HRID 2379007Notes

Reaction equation

HRID 2379007 reaction equation
[CH:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH2:4][CH2:3][N:2]=1.[C:11]1([CH3:22])[CH:16]=[CH:15][C:14]([S:17]([O:20]C)(=[O:19])=[O:18])=[CH:13][CH:12]=1>CO>[C:11]1([CH3:22])[CH:12]=[CH:13][C:14]([S:17]([O-:20])(=[O:18])=[O:19])=[CH:15][CH:16]=1.[CH3:11][N+:2]1[CH2:3][CH2:4][C:5]2[C:10](=[CH:9][CH:8]=[CH:7][CH:6]=2)[CH:1]=1

Participants

4

Reactant 2

HCID 6645Methyl p-toluenesulfonateHCID 767053,4-Dihydroisoquinoline

Product 1

HCID 10543528N-Methyl 3,4-dihydroisoquinolinium p-toluene sulfonateYield 88%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Conditions

Temperature
0 °C

Procedure

The title compound was prepared using the procedure described by Koelsch et al in J. Am. Chem. Soc. (1953) 75, 2095. In a 250-ml one-necked round-bottomed flask equipped with a magnetic stir bar and a reflux condenser were placed 3,4-dihydroisoquinoline (8.27 grams, 63 mmol) and 40 ml of methanol. The mixture was stirred and cooled to 0° C. A solution of methyl p-toluenesulfonate (11.73 g, 63 mmol) and 70 ml of methanol was added dropwise. The color of the solution remained clear and yellow. The mixture was heated to reflux for 6 hours. The methanol was then removed in vacuo to provide a quantitative yield (20 g) of an off-white solid (mp 115°-119° C.). The solid was pulverized and washed with 40 ml of acetone at room temperature. Suction filtration provided a white solid in 88% yield: mp 124°-127° C.

Workup

  1. customIn a 250-ml one-necked round-bottomed flask equipped with a magnetic stir bar and a reflux condenser
  2. temperatureThe mixture was heated
  3. temperatureto reflux for 6 hours
  4. customThe methanol was then removed in vacuo

Sources & evidence

ORD record
ord-be878fa92dc440c6837e20987228d77c
Source dataset
uspto-grants-1994_11
Patent number
US05360568

Reaction notes

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