Reacción #428199

Ecuación de reacción

(S)-5-(tert-butyldimethylsilyloxy)-4-(3-(2-chloro-3-fluorobenzyl)-1-methylureido)pentanoic acid

HBTU

1-N-Boc-piperazine

DIEA

→

(S)-tert-butyl 4-(5-(tert-butyldimethylsilyloxy)-4-(3-(2-chloro-3-fluorobenzyl)-1-methylureido)pentanoyl)piperazine-1-carboxylate

Rendimiento 68.3%

Disolventes

DMF

brine

Ether

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe organic layer was dried
2. 2
   Concentraciónconcentrated
3. 3
   OtroThe residue was purified on silica gel column
4. 4
   workup.ADDITIONa mixture of hexane and EtOAc

Procedimiento

To a solution of (S)-5-(tert-butyldimethylsilyloxy)-4-(3-(2-chloro-3-fluorobenzyl)-1-methylureido)pentanoic acid (4.46 g, 10 mmol, 1.0 equiv.) in DMF (50 mL), was added HBTU (5.69 g, 15 mmol, 1.5 equiv.), 1-N-Boc-piperazine (2.79 g, 15 mmol, 1.5 equiv.) and DIEA (5.21 mL, 30 mmol, 3.0 equiv.) in sequence. The reaction was completed in 15 min. Ether (100 mL) and brine (100 mL) were added to the reaction mixture. The organic layer was dried and concentrated. The residue was purified on silica gel column using a mixture of hexane and EtOAc to give (S)-tert-butyl 4-(5-(tert-butyldimethylsilyloxy)-4-(3-(2-chloro-3-fluorobenzyl)-1-methylureido)pentanoyl)piperazine-1-carboxylate (4.2 g, 68%). LRMS (M+H+) m/z 615.2.

Fuente