Реакция #452144

Уравнение реакции

2-propanol

ethyl acetate

diethyl 4-(4-benzofurazanyl)-2-(diethoxymethyl)-1,4-dihydro-6-(trifluoromethyl)-3,5-pyridinedicarboxylate

hydrochloric acid

→

title compound

Выход 7.1%

Diethyl 4-(4-benzofurazanyl)-2-formyl-1,4-dihydro-6-(trifluoromethyl)-3,5-pyridinedicarboxylate

Выход 7.1%

Растворители

tetrahydrofuran

Условия реакции

Обработка

1. 1
   Температураthe resulting solution heated
2. 2
   Температураat reflux
3. 3
   ДругоеThe organic phase was separated
4. 4
   Промывкаwashed with water, saturated aqueous sodium bicarbonate solution, brine
5. 5
   Сушкаdried (MgSO4)
6. 6
   ДругоеEvaporation of the solvent
7. 7
   workup.WAITleft an oil (7.5 g) which
8. 8
   Другоеwas purified by chromatography on silica (300 g)
9. 9
   Другоеether-petroleum ether (60°-80°)
10. 10
    ДругоеThe major component was obtained as an oil which
11. 11
    ДругоеRecrystallisation from 2-propanol

Методика

To a solution of diethyl 4-(4-benzofurazanyl)-2-(diethoxymethyl)-1,4-dihydro-6-(trifluoromethyl)-3,5-pyridinedicarboxylate (7.6 g, 14.5 mmoles) in tetrahydrofuran (100 ml) was added 25% aqueous hydrochloric acid solution (100 ml) and the resulting solution heated at reflux. After 1.5 hours the cooled solution was poured into ethyl acetate (200 ml). The organic phase was separated and washed with water, saturated aqueous sodium bicarbonate solution, brine and dried (MgSO4). Evaporation of the solvent left an oil (7.5 g) which was purified by chromatography on silica (300 g) using ether-petroleum ether (60°-80°) as eluent. The major component was obtained as an oil which gave a solid on trituration with 2-propanol. Recrystallisation from 2-propanol gave the title compound (0.45 g) as yellow crystals mp 94°-5°.

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