Réaction #2083095

Équation de réaction

borontrifluoride etherate

2-(4-methoxybenzyl)-1,3,3-trimethyl-4-piperidone

methanol

sodium hydroxide

→

4,4-dimethoxy-2-(4-methoxybenzyl)-1,3,3-trimethylpiperidine

Conditions de réaction

Traitement

1. 1
   Températurethe temperature being maintained below 35° C
2. 2
   workup.ADDITIONare added
3. 3
   Filtrationare filtered off
4. 4
   Lavagewashed with methanol
5. 5
   AutreThe filtrate is evaporated under reduced pressure
6. 6
   workup.ADDITIONafter addition of 500 ml water
7. 7
   Extractionextracted 3 times with 150 ml of chloroform
8. 8
   SéchageThe chloroform phases are dried over sodium sulphate
9. 9
   Autreevaporated under reduced pressure
10. 10
    AutreAfter crystallization
11. 11
    Autrefrom 200 ml petrol ether (b.p.: 60°-80° C.) and further recrystallization there

Mode opératoire

40 ml of borontrifluoride etherate are added drop-wise over 20 minutes and with stirring to a solution of 52.2 g (0.2 Mol) 2-(4-methoxybenzyl)-1,3,3-trimethyl-4-piperidone in 500 ml methanol, the temperature being maintained below 35° C. After stirring for 16 hours at room-temperature 40 g pulverized sodium hydroxide are added. After stirring for a further 30 minutes the obtained sodium salts are filtered off and washed with methanol. The filtrate is evaporated under reduced pressure and after addition of 500 ml water, extracted 3 times with 150 ml of chloroform. The chloroform phases are dried over sodium sulphate and evaporated under reduced pressure. After crystallization from 200 ml petrol ether (b.p.: 60°-80° C.) and further recrystallization there are obtained 25.4 g 4,4-dimethoxy-2-(4-methoxybenzyl)-1,3,3-trimethylpiperidine, m.p.: 91°-92.5° C.

Source