Reaktion #56503

Reaktionsgleichung

hydrochloric acid

4-carbobenzoxypiperazine-2-carboxylic acid hydrochloride

2-chloro-3-nitropyridine

triethyl amine

→

title product

1-(3-Nitro-2-pyridinyl)-4-carbobenzoxypiperazine-2-carboxylic acid

Lösungsmittel

dimethyl sulfoxide

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONThe mixture is diluted with 400 ml
2. 2
   Extraktionextracted repeatedly with ether
3. 3
   TrocknenThe combined ether extracts are dried (MgSO4)
4. 4
   Einengenconcentrated
5. 5
   SonstigeThe residue is crystallized from ethyl acetate/heptane
6. 6
   Sonstigeto give 6.3 g

Vorschrift

A solution of 6.0 g. of 4-carbobenzoxypiperazine-2-carboxylic acid hydrochloride, 3.3 g. of 2-chloro-3-nitropyridine and 15 ml. of triethyl amine in 100 ml. of dimethyl sulfoxide is heated at 60° with stirring for 18 hours. The mixture is diluted with 400 ml. of water, acidified to pH 3 with concentrated hydrochloric acid, and extracted repeatedly with ether. The combined ether extracts are dried (MgSO4) and concentrated. The residue is crystallized from ethyl acetate/heptane to give 6.3 g. of the title product, m.p. 145°-147°.

Quelle