Реакция #314751

Уравнение реакции

arecoline

1-bromo-3,4-dichlorobenzene

magnesium

HCl

→

( 1 )

Выход 25.0%

(±)-Cis-1-methyl-4-(3,4-dichlorophenyl)-piperidine-3-carboxylic acid methyl ester

Выход 25.0%

( 2 )

Выход 10.0%

(±)-Trans-1-methyl-4-(3,4-dichlorophenyl)-piperidine-3-carboxylic acid methyl ester

Выход 10.0%

Растворители

toluene

diethyl ether

diethyl ether

Условия реакции

Обработка

1. 1
   ТемператураThe mixture was heated
2. 2
   Температураat reflux for 20 minutes
3. 3
   Другоеthe internal temperature between −40° C. and −30° C
4. 4
   ДругоеThe phases were then separated
5. 5
   workup.ADDITIONthe aqueous phase was added ammonia (aq) until basic pH
6. 6
   Экстракцияextracted with dichloromethane (4×100 ml)
7. 7
   Сушкаdried with magnesium sulfate
8. 8
   Другоеevaporated to an oil
9. 9
   ДругоеThe isomers (1) and (2) were separated by column chromatography (petroleum ether, ether, triethylamine 70:25:5)

Методика

A stirred suspension of magnesium turnings (3.4 g, 142 mmol) in diethyl ether (20 ml) was added a solution of 1-bromo-3,4-dichlorobenzene (29 g, 130 mmol) in diethyl ether (150 ml). The mixture was heated at reflux for 20 minutes and then cooled at −40° C. A solution of arecoline (10 g, 65 mmol) in toluene (100 ml) was added slowly while keeping the internal temperature between −40° C. and −30° C. The reaction mixture was stirred at −20° C. for 6 hours and then added 4 N HCl (50 ml). The phases were then separated and the aqueous phase was added ammonia (aq) until basic pH and extracted with dichloromethane (4×100 ml), dried with magnesium sulfate and evaporated to an oil. The isomers (1) and (2) were separated by column chromatography (petroleum ether, ether, triethylamine 70:25:5) to give 5.0 g (25%) of (1) (mp. 70-75° C.) and 2.0 g (10%) of (2) (oil).

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