Reaktion #2194071

Reaktionsgleichung

1,2,3,6-tetrahydro-4-(3-methoxyphenyl)-1-methylpyridine

n-propylbromide

n-butyllithium

→

1,2,3,4-tetrahydro-4-(3-methoxyphenyl)-1-methyl-4-propylpyridine

Ausbeute 75.0%

Lösungsmittel

THF

tetrahydrofuran

hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added to a dry, nitrogen
2. 2
   Sonstigepurged
3. 3
   Sonstige22 liter reaction flask
4. 4
   Sonstigeequipped with a stirrer
5. 5
   workup.ADDITIONlow temperature thermometer, and addition funnel
6. 6
   workup.ADDITIONwas added at a rate so as
7. 7
   Temperaturto maintain the temperature below -5° C
8. 8
   Sonstigeremained below -5° C
9. 9
   workup.STIRRINGThe reaction mixture was stirred for 10 minutes at -5° C.
10. 10
    Sonstigecarefully quenched by the addition of 1.5 liters of water
11. 11
    Sonstigeto destroy any excess n-butyllithium
12. 12
    SonstigeThe organic phase was separated
13. 13
    Waschenwashed with 1.5 liters of water, 1.5 liters of saturated sodium chloride solution
14. 14
    Trocknendried over 500 g of anhydrous sodium sulfate
15. 15
    SonstigeEvaporation of the solvent

Vorschrift

A solution of 900 g (4.43 mol) of 1,2,3,6-tetrahydro-4-(3-methoxyphenyl)-1-methylpyridine dissolved in 10.8 liters of dry THF was added to a dry, nitrogen purged 22 liter reaction flask equipped with a stirrer, low temperature thermometer, and addition funnel. The temperature of the reaction mixture was lowered to approximately -10° C. whereupon 3.04 liters of 1.6 molar n-butyllithium in hexane was added at a rate so as to maintain the temperature below -5° C. The resulting deep red solution was stirred for 15 minutes at -5° C. and 572 g (4.65 mol) of n-propylbromide in 2.4 liters of dry tetrahydrofuran were added at such a rate so that the temperature remained below -5° C. The reaction mixture was stirred for 10 minutes at -5° C. and then carefully quenched by the addition of 1.5 liters of water to destroy any excess n-butyllithium. The organic phase was separated, washed with 1.5 liters of water, 1.5 liters of saturated sodium chloride solution and dried over 500 g of anhydrous sodium sulfate. Evaporation of the solvent gave 1126 g of crude 1,2,3,4-tetrahydro-4-(3-methoxyphenyl)-1-methyl-4-propylpyridine (75% pure). 78% yield. bp=113° C./0.2 torr. NMR: (CDCl3) δ0.80 (3H,t), 2.57 (3H,s), 3.80 (3H,s), 4.58 (1H,d,A of AX, J =8), 5.95 (1H,d,X of AX, J=8), 6.8-7.3 (4H, m, aryl).

Quelle