반응 #2459982

반응 방정식

n-butyllithium hexane

N-(3-methylbenzyl)-imidazole

TMEDA

pivalaldehyde

→

1-(1-imidazolyl)-1-(3-tolyl)-3,3-dimethylbutan-2-ol

수율 8.3%

용매

water

THF

THF

반응 조건

후처리

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for 20 minutes at about -70° C.
3. 3
   온도to warm up to room temperature in the course of 2 hours
4. 4
   온도while cooling
5. 5
   추출the resulting mixture was extracted with ether
6. 6
   추출The residue (9.3 g) from the ether extract
7. 7
   기타was crystallized from a diisopropyl ether/hexane mixture
8. 8
   기타The residue from the mother liquor was recrystallized from a diisopropyl ether/acetonitrile solution
9. 9
   기타the crystalline product isolated in this procedure
10. 10
    기타was then recrystallized twice from acetonitrile

실험 절차

39 ml (60 mmol) of a 1.55 molar n-butyllithium/hexane solution were added dropwise to a solution of 5.17 g (30 mmol) of N-(3-methylbenzyl)-imidazole and 3.49 g (30 mmol) of TMEDA in 60 ml of absolute THF at -70° C. The mixture was stirred for 30 minutes at about -70° C., after which a solution of 3.80 g (33 mmol) of 75% strength pivalaldehyde in 30 ml of absolute THF was added dropwise at about -70° C. in the course of 20 minutes, stirring was continued for 20 minutes at about -70° C. and the mixture was allowed to warm up to room temperature in the course of 2 hours. Thereafter, water was added, while cooling, and the resulting mixture was extracted with ether. The residue (9.3 g) from the ether extract was crystallized from a diisopropyl ether/hexane mixture. This gave 2.2 g of crystals, which consisted of about 90% of a by-product, 1-(3-methylbenzyl)-2-(1-hydroxy-2,2-dimethylprop-1-yl)-imidazole. The residue from the mother liquor was recrystallized from a diisopropyl ether/acetonitrile solution, and the crystalline product isolated in this procedure was then recrystallized twice from acetonitrile. 0.64 g (=8.3% of theory) of pure 1-(1-imidazolyl)-1-(3-tolyl)-3,3-dimethylbutan-2-ol of melting point 126° C. was obtained in this manner.

출처