Reaktion #1547366

Reaktionsgleichung

methyl 4-(2,5-dihydroxy-3,4-dimethoxy-6-methylbenzyl)-1-piperazinecarbodithioate

hydrochloric acid

methanol

→

desired compound

Ausbeute 77.6%

Methyl 4-(5,6-dimethoxy-3-methyl-1,4-benzoquinonylmethyl)-1-piperazinecarbodithioate

Ausbeute 77.6%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was chilled with ice
2. 2
   Sonstigelower than 50° C.
3. 3
   workup.DISTILLATIONto distill off methanol
4. 4
   workup.ADDITIONTo the residue was added 50 ml of ethyl acetate
5. 5
   workup.ADDITIONfurther added portionwise a saturated aqueous sodium hydrogen carbonate solution
6. 6
   SonstigeA precipitated brownish red solid was removed by filtration
7. 7
   WaschenThus obtained organic filtrate was washed with water
8. 8
   Trocknena saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate
9. 9
   workup.DISTILLATIONto distill off the solvent
10. 10
    SonstigeThe residue was crystallized from ethanol
11. 11
    Filtrationcollected by filtration

Vorschrift

To 700 mg (1.88 mmol.) of methyl 4-(2,5-dihydroxy-3,4-dimethoxy-6-methylbenzyl)-1-piperazinecarbodithioate were added 7 ml of 1-N hydrochloric acid and 17 ml of methanol. The mixture was chilled with ice, and to the mixture was dropwise added a solution of 1.76 g (7.52 mmol.) of FeCl3.6H2O in 5 ml of water. The resulting homogeneous red-colored solution was stirred for 30 min. and placed under reduced pressure at a temperature of lower than 50° C. to distill off methanol. To the residue was added 50 ml of ethyl acetate, and further added portionwise a saturated aqueous sodium hydrogen carbonate solution to adjust the solution to pH 10. A precipitated brownish red solid was removed by filtration. Thus obtained organic filtrate was washed with water and a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, and placed under reduced pressure to distill off the solvent. The residue was crystallized from ethanol, and collected by filtration, to give 540 mg of the desired compound as an orange-brown crystalline powder, m.p. 115°-116° C., yield 77.6%.

Quelle