Reaktion #2154357

Reaktionsgleichung

AlCl3

AlCl3

hydrochloric acid

1,1,4,4,6-pentamethyl-1,2,3,4-tetrahydronaphthalene

acetyl chloride

→

1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-2-yl)ethanone

Ausbeute 88.0%

Lösungsmittel

ethyl acetate

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTo a 250 ml three-necked round bottomed flask fitted with a magnetic stirring bar and a reflux condenser
2. 2
   Temperaturheated
3. 3
   Temperaturat reflux for 15 min
4. 4
   Sonstigethe completion of the reaction
5. 5
   SonstigeThe cooled reaction mixture
6. 6
   workup.STIRRINGStirring
7. 7
   workup.WAITwas yellow 15 min
8. 8
   ExtraktionThe organic layer was extracted with ethyl acetate (2×100 ml)
9. 9
   Trocknendried over MgSO4
10. 10
    Filtrationfiltered
11. 11
    Einengenconcentrated in vacuo
12. 12
    workup.DISTILLATIONKugelrohr distillation (80-120° C., 3×10−4 torr)

Vorschrift

To a 250 ml three-necked round bottomed flask fitted with a magnetic stirring bar and a reflux condenser containing acetyl chloride (2.3 g, 29.7 mmol) and 50 ml of DCM was added 1,1,4,4,6-pentamethyl-1,2,3,4-tetrahydronaphthalene 1b (5 g, 24.8 mmol) followed by slow addition (ca. 0.5 g portions) of AlCl3 (7.5 g, 56.2 mmol). The brown mixture was stirred for 30 min and then heated at reflux for 15 min. Additional AlCl3 (1-2 g) was necessary to effect the completion of the reaction. The cooled reaction mixture was poured into 200 ml of vigorously stirred ice water followed by acidification with 20% aqueous hydrochloric acid 50 ml and addition of 100 ml of ethyl acetate. Stirring was continued until the organic layer was yellow 15 min. The organic layer was extracted with ethyl acetate (2×100 ml), dried over MgSO4, filtered and concentrated in vacuo. Kugelrohr distillation (80-120° C., 3×10−4 torr) gave an analytically pure sample of 1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-2-yl)ethanone 5.31 g (88%) as a white solid; m.p. 54-56° C.

Quelle