Reaktion #318211

Reaktionsgleichung

N,N'-dicyclohexylcarbodiimide

HCl

2,5-dimethoxyaniline

triethylamine

carbon disulfide

→

2,5-dimethoxyphenylisothiocyanate

Ausbeute 57.6%

Lösungsmittel

hexane

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigekept at 5° C.
2. 2
   workup.STIRRINGstirring
3. 3
   workup.WAITwas continued for another 3 hours
4. 4
   Sonstigean aqueous layer was separated
5. 5
   workup.ADDITIONn-Hexane (100 ml) was further added to an organic layer
6. 6
   Sonstigeprecipitates
7. 7
   Filtrationwere filtered off
8. 8
   workup.DISTILLATIONThe solvents were distilled off under reduced pressure
9. 9
   Sonstigea crude oily product was obtained
10. 10
    SonstigeSeparation and purification by chromatography

Vorschrift

To a solution of 2,5-dimethoxyaniline (61.2 g, 0.4 mol) and triethylamine (75 ml, 0.48 mol) in 300 ml of tetrahydrofuran was added carbon disulfide (91.2 g, 0.48 mol) at 5° C. and stirring was continued for 3 hours. To the reaction mixture kept at 5° C. was added N,N'-dicyclohexylcarbodiimide (99 g, 0.48 mol) and stirring was continued for another 3 hours. To the reaction mixture were added 2N HCl solution (100 ml) and hexane (100 ml) and an aqueous layer was separated. n-Hexane (100 ml) was further added to an organic layer and precipitates were filtered off. The solvents were distilled off under reduced pressure and a crude oily product was obtained. Separation and purification by chromatography using a silica gel column gave oily 2,5-dimethoxyphenylisothiocyanate (45 g, yield 57%).

Quelle