3,3-dimethyl-4H-isoquinoline

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a nitrogen-blanketed mixture of potassium hydroxide (KOH, 30 g) and methanol (CH3OH, 60 mL) was added of N-toluenesulfonyl-3,3-dimethyl-1,2,3,4-tetrahydroisoquinoline (4.0 g, 0.013 mol.). The reaction mixture was heated at reflux for 17 hours and the reaction was followed by gas chromatography. The reaction mixture was cooled to ambient temperature, quenched with water (100 mL) and 10% HCl was slowly added until pH=7 was obtained. The aqueous mixture was extracted with methylene chloride (3×100 mL) and the organic layers were combined and stirred with charcoal and sodium sulfate (Na2 SO4). The solution was filtered through celite and the filtrate was concentrated (25°/150 torr) to give 3,3-dimethyl-3,4-dihydroisoquinoline (1.79 g, yield=90%). The reaction mixture was heated at reflux for 17 hours quenched with water (100 mL) and 10% HCl was slowly added until pH=7 was obtained The aqueous mixture was extracted with methylene chloride (3×100 mL) The solution was filtered through celite the filtrate was concentrated (25°/150 torr)

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of potassium nitrate (2.53 g) in sulfuric acid (14 ml ) at 0° C. was added dropwise a solution of 3,4-dihydro-3,3-dimethyl isoquinoline (3.68 g; 23 mmol) [prepared according to the procedure of T. J. N. Watson, J. Org. Chem., 1998, 63, 406] in sulfuric acid (13.5 ml). The resultant solution was stirred at room temperature for 1.5 h and then heated to 60° C. for 4.5 h. The solution was then cooled to room temperature, and poured on to ice.; 0.880 ammonia was added until the solution was neutral, and the product was extracted into dichloromethane (×3). The combined organic phases were, dried over magnesium sulphate, and then evaporated in vacuo to afford the title compound (4.22 g). 1H NMR (CDCl3)δ: 1.27 (6H, s), 2.85 (2H, s), 7.34 (1H, d, J=8 Hz), 8.17 (1H, d, J=2Hz), 8.23 (1H, dd, J=8, 2Hz), 8.33 (1H, s). prepared The solution was then cooled to room temperature poured on to ice the product was extracted into dichloromethane (×3) dried over magnesium sulphate evaporated in vacuo

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of potassium nitrate (2.53 g) in sulfuric acid (14 ml ) at 0° C. was added dropwise a solution of 3,4-dihydro-3,3-dimethyl isoquinoline (3.68 g; 23 mmol) [prepared according to the procedure of T. J. N. Watson, J. Org. Chem., 1998, 63, 406] in sulfuric acid (13.5 ml). The resultant solution was stirred at room temperature for 1.5 h and then heated to 60° C. for 4.5 h. The solution was then cooled to room temperature, and poured on to ice.; 0.880 ammonia was added until the solution was neutral, and the product was extracted into dichloromethane (×3). The combined organic phases were, dried over magnesium sulphate, and then evaporated in vacuo to afford the title compound (4.22 g). 1H NMR (CDCl3)δ: 1.27 (6H, s), 2.85 (2H, s), 7.34 (1H, d, J=8 Hz), 8.17 (1H, d, J=2Hz), 8.23 (1H, dd, J=8, 2Hz), 8.33 (1H, s). prepared The solution was then cooled to room temperature poured on to ice the product was extracted into dichloromethane (×3) dried over magnesium sulphate evaporated in vacuo