반응 #94452

반응 방정식

α,α'-dibromo-o-xylene

THF

diisopropylamine

n-butyllithium

isobutyronitrile

THF

dry ice

→

1,2-bis(2-methyl-2-cyanopropyl)benzene

수율 94.0%

용매

hexane

반응 조건

후처리

1. 1
   기타In a dry 1-liter flask, equipped with a large magnetic stirrer, a reflux condenser
2. 2
   기타capped with a nitrogen bubbler, an addition funnel, and a syringe adapter
3. 3
   온도The mixture was cooled in a dry ice bath
4. 4
   workup.STIRRINGAfter the mixture had stirred for 1 hr
5. 5
   workup.STIRRINGof stirring
6. 6
   workup.STIRRINGThe mixture was stirred for 1 hr at -76°
7. 7
   workup.STIRRINGAfter an additional 2 days of stirring at room temperature
8. 8
   workup.DISTILLATIONthe mixture was distilled on the water
9. 9
   기타to remove the solvent
10. 10
    workup.DISSOLUTIONDissolving of the resulting residue in 400 ml of chloroform
11. 11
    추출followed by 3 extractions of the chloroform solution with 200 ml of water (with HCl acidification
12. 12
    추출during the first extraction),
13. 13
    건조drying over anhydrous magnesium sulfate, and removal of the solvent on the water

실험 절차

In a dry 1-liter flask, equipped with a large magnetic stirrer, a reflux condenser capped with a nitrogen bubbler, an addition funnel, and a syringe adapter, was placed 570 ml of anhydrous THF, and 26.5 ml of diisopropylamine (via syringe). The mixture was cooled in a dry ice bath, and with stirring, 73.1 ml of 2.6 molar n-butyllithium in hexane was added via syringe. After the mixture had stirred for 1 hr, a solution of 13.1 g of freshly distilled isobutyronitrile in 40 ml of THF was added in 25 min. Following another 35 min of stirring, 25.0 g of α,α'-dibromo-o-xylene was added all at once. The mixture was stirred for 1 hr at -76°, and then overnight as the dry ice bath warmed to room temperature. After an additional 2 days of stirring at room temperature, the mixture was distilled on the water pump to remove the solvent. Dissolving of the resulting residue in 400 ml of chloroform, followed by 3 extractions of the chloroform solution with 200 ml of water (with HCl acidification during the first extraction), drying over anhydrous magnesium sulfate, and removal of the solvent on the water pump, gave 21.50 g (94%) of crude 1,2-bis(2-methyl-2-cyanopropyl)benzene melting at 76°-80°. Refluxing of this material with Darco in 425 ml of cyclohexane, followed by filtration, evaporation of the filtrate to 250 ml, seeding and then cooling to 8°-10°, gave 18.30 g of the product melting at 81.5-82°.

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