Reaktion #54828

Reaktionsgleichung

sodium nitrite

hydrofluoric acid

ethyl 3-amino-4-cyclohexylphenylglyoxylate

boric acid

hydrochloric acid

→

ethyl 3-fluoro-4-cyclohexylphenylglyoxylate

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONTo this mixture is rapidly added a solution of 10.4 g
2. 2
   Filtrationfiltered
3. 3
   Waschenwashed with 3 × 25 ml
4. 4
   workup.ADDITIONThe residual cake is then treated in vacuo
5. 5
   SonstigeThe treated cake is then placed in a distilling flask
6. 6
   Temperaturheated
7. 7
   workup.DISTILLATIONAfter the decomposition, the residue is then fractionally distilled

Vorschrift

To 44.2 g. (0.15 moles) of ethyl 3-amino-4-cyclohexylphenylglyoxylate is added at 0° C. 44 ml. of 1.5 moles of concentrated hydrochloric acid. The reaction mixture is maintained at 0° C. and the diazonium salt is prepared with 23.2 g. (0.32 moles) of 95% sodium nitrite in 80 ml. of water. To this mixture is rapidly added a solution of 10.4 g. (0.17 moles) of boric acid dissolved in 22 g. (0.66 moles) of 60% hydrofluoric acid. The reaction mixture is then stirred for 1/2 hour and filtered, washed with 3 × 25 ml. of water, 2 × 25 ml. of methanol and 25 ml. of ether. The residual cake is then treated in vacuo. The treated cake is then placed in a distilling flask and heated to permit spontaneous decomposition. After the decomposition, the residue is then fractionally distilled to obtain ethyl 3-fluoro-4-cyclohexylphenylglyoxylate.

Quelle