Réaction #10879

Équation de réaction

4-(4-aminophenyl)-1-piperazinecarboxylic acid, 1,1-dimethylethyl ester

1,1′-thiocarbonyldiimidazole

→

4-(4-isothio-cyanatophenyl)-1-piperazinecarboxylic acid, 1,1-dimethylethyl ester

Rendement 104.2%

Solvants

N,N-dimethylformamide

N,N-dimethylformamide

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONAfter the addition
2. 2
   Autrethe cooling bath was removed
3. 3
   workup.ADDITIONThe mixture was poured into ice-water (1 L)
4. 4
   workup.STIRRINGstirred for 30 minutes
5. 5
   Extractionextracted with diethyl ether
6. 6
   SéchageThe combined extracts were dried over Na2SO4
7. 7
   Autreevaporated in vacuo

Mode opératoire

A solution of 4-(4-aminophenyl)-1-piperazinecarboxylic acid, 1,1-dimethylethyl ester (15 g, 54.1 mmol) (from Step B above) in N,N-dimethylformamide (120 mL) was added dropwise to a cooled (−15° C.) solution of 1,1′-thiocarbonyldiimidazole (9.66 g, 54.2 mmol) (Aldrich) in N,N-dimethylformamide (40 mL). After the addition was complete, the cooling bath was removed and the solution was stirred for 1 h. The mixture was poured into ice-water (1 L), stirred for 30 minutes, and extracted with diethyl ether. The combined extracts were dried over Na2SO4, and evaporated in vacuo to provide 4-(4-isothio-cyanatophenyl)-1-piperazinecarboxylic acid, 1,1-dimethylethyl ester (18 g, 94%).

Source