Reaction #657274

Reaction equation

p-toluenesulphonic acid

2-[2-(2,6-Dimethyl-piperidin-1-yl) acetylamino]-propanoic acid

2-[2-(2,6-Dimethyl-piperidin-1-yl)acetylamino]-propanoic acid

N-Hydroxysuccinimide

N,N′-Dicyclohexylcarbodiimide

→

2-[2-(2,6-Dimethyl-piperidin-1-yl)acetylamino]-propanoic acid-(2,5-dioxo-pyrrolidine-1-yl)-ester

Solvents

dichloromethane

toluene

water

Conditions

Workup

1. 1
   workup.ADDITIONwere added to the residue
2. 2
   FiltrationThe solution was filtered
3. 3
   Otherthe filtrate was evaporated in vacuo to dryness
4. 4
   OtherThe product was recrystallised from diisopropylether

Procedure

4.75 g (25 mMol) p-toluenesulphonic acid were heated under reflux for 1 h in 20 ml toluene using a water separator. After having evaporating the solvent, 6.30 g (25 mMol) 2-[2-(2,6-Dimethyl-piperidin-1-yl) acetylamino]-propanoic acid (27), 2.88 g (25 mMol) N-Hydroxysuccinimide and 5.15 g (25 mMol) N,N′-Dicyclohexylcarbodiimide were added to the residue dissolved in 100 ml dichloromethane. The reaction mixture was stirred for 16 h at room temperature. The solution was filtered and the filtrate was evaporated in vacuo to dryness. The product was recrystallised from diisopropylether.

Source