反应详情

温度

100 °C

4.30 g (15.3 mmol) of 2-methyl-6-(4-trifluoromethyl-phenyl)-nicotinic acid (prepared from 2-methyl-6-(4-trifluoromethyl-phenyl)-nicotinic acid methyl ester (example 1L]) in analogy to the procedure described in example 53B]) was dissolved in 85 ml of 2-methyl-2-propanol and 3.18 ml=2.32 g (22.9 mmol) of triethylamine was added. After 5 min., 4.97 ml=6.64 g (22.9 mmol) of diphenylphosphoryl azide (95%) was added. The reaction mixture was then stirred at reflux (oil bath 100° C.). After 10 min., 0.53 g (3.1 mmol) of anhydrous 4-toluene sulfonic acid was added and stirring continued for 1 hour at reflux. The solvent was then completely removed by evaporation at high vacuum; the residue was dissolved in Et2O and washed with H2O, 1N HCl, and NaHCO3 solution. The combined organic phases were dried over anhydrous magnesium sulfate and evaporated. The crude product was purified by crystallization (EtOAc, n-heptane) to give 4.05 g of the title compound as colorless solid.

1. waitAfter 10 min.
2. stirringstirring
3. waitcontinued for 1 hour
4. temperatureat reflux
5. customThe solvent was then completely removed by evaporation at high vacuum
6. dissolutionthe residue was dissolved in Et2O
7. washwashed with H2O, 1N HCl, and NaHCO3 solution
8. dry with materialThe combined organic phases were dried over anhydrous magnesium sulfate
9. customevaporated
10. customThe crude product was purified by crystallization (EtOAc, n-heptane)