Reaction #3038

Reaction equation

carbon disulfide

diethyl ether

ethanolamine

→

desired subtitled intermediate

N-(2-hydroxyethyl)rhodanine

Solvents

ethanol

Conditions

Workup

1. 1
   Otherat ambient temperature
2. 2
   Otherfor 16 hours
3. 3
   Otherthe resulting top layer was decanted
4. 4
   Washthe residual oil washed twice with 50 ml of diethyl ether
5. 5
   workup.ADDITIONTo the oil was added a solution of 71 g of chloroacetic acid in 150 ml of 5N sodium hydroxide at 0° C
6. 6
   OtherThe cooling bath was removed
7. 7
   workup.ADDITIONThe mixture was poured into 400 ml of 6N hydrochloric acid
8. 8
   Temperaturethe resulting mixture heated to 91° C. for 20 minutes
9. 9
   OtherThe heat was removed
10. 10
    workup.WAITto stand for 5 hours at ambient temperature
11. 11
    OtherAn oily organic layer was separated from the aqueous layer
12. 12
    Extractionthe aqueous layer extracted twice with 250 ml of ethyl acetate
13. 13
    Washwashed twice with a saturated sodium chloride solution
14. 14
    Otherdried
15. 15
    Concentrationconcentrated in vacuo

Procedure

Sixty milliliters of carbon disulfide were added to 200 ml of diethyl ether. The solution was chilled to -5° C. and slowly added to a solution of 138 ml of ethanolamine in 250 ml of ethanol. After holding the mixture at ambient temperature for 16 hours, the resulting top layer was decanted and the residual oil washed twice with 50 ml of diethyl ether. To the oil was added a solution of 71 g of chloroacetic acid in 150 ml of 5N sodium hydroxide at 0° C. The cooling bath was removed and the reaction was allowed to stand for 75 minutes. The mixture was poured into 400 ml of 6N hydrochloric acid and the resulting mixture heated to 91° C. for 20 minutes. The heat was removed, and the solution allowed to stand for 5 hours at ambient temperature. An oily organic layer was separated from the aqueous layer and the aqueous layer extracted twice with 250 ml of ethyl acetate. The organic layers were combined, washed twice with a saturated sodium chloride solution, dried and concentrated in vacuo to provide 113.4 g of the desired subtitled intermediate, which was used without further purification.

Source