Reacción #55625

Ecuación de reacción

carbobenzoxy-β-alanine

isobutylchloroformate

L-proline t-butyl ester hydrochloride

N-methylmorpholine

→

carbobenzoxy-β-alanyl-L-proline t-butyl ester

Disolventes

triethylamine

dimethylformamide

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

1. 1
   Otrothe resulting reaction mixture
2. 2
   workup.STIRRINGis stirred
3. 3
   workup.STIRRINGis thereafter stirred overnight
4. 4
   OtroThe solvent of the reaction mixture is evaporated in vacuo at 30°-35°
5. 5
   workup.DISSOLUTIONThe residue is dissolved in 800 ml
6. 6
   Lavadoof ethyl acetate which is washed with (2×150 ml.) a 10% citric acid solution
7. 7
   SecadoThe organic layer is dried with anhydrous magnesium sulfate
8. 8
   Otrothe solvent evaporated

Procedimiento

4.46 g. of carbobenzoxy-β-alanine is dissolved in 20 ml. of tetrahydrofuran and the resulting solution cooled to -10° C. With constant stirring of the solution, 2.4 ml. of N-methylmorpholine followed by 2.6 ml. of isobutylchloroformate are added and the resulting reaction mixture is stirred thereafter for approximately 5 minutes at -10° C. 4.16 g. of L-proline t-butyl ester hydrochloride in 20 ml. of dimethylformamide and 2.8 ml. of triethylamine is added to the reaction mixture which is thereafter stirred overnight, while slowly warming to room temperature. The solvent of the reaction mixture is evaporated in vacuo at 30°-35°. The residue is dissolved in 800 ml. of ethyl acetate which is washed with (2×150 ml.) a 10% citric acid solution, with (1×150 ml.) water, with (2×150 ml.) saturated solution of sodium bicarbonate and then with (2×100 ml.) water. The organic layer is dried with anhydrous magnesium sulfate and the solvent evaporated to yield carbobenzoxy-β-alanyl-L-proline t-butyl ester.

Fuente