2-Amino-5-chloropyridine

Chemical properties

beige to beige-brown crystalline powder

The Uses of 2-Amino-5-chloropyridine

5-Chloro-2-pyridinamine is a useful synthetic intermediate. It can be used to synthesize zopiclone (Z700500) which is a cyclopyrrolone member of a family of non-benzodiazepine GABAA receptor agonists.

Preparation

2-amino-5-chloro-pyridine is prepared by adopting 2-aminopyridine as a raw material and using hydrochloric acid and sodium hypochlorite for an oxidative chlorination reaction. The method mainly includes the following steps: at 10℃, slowly and dropwise adding a certain amount of concentrated hydrochloric acid in a mixed solution of 2-aminopyridine and NaClO, conducting a reaction at constant temperature for 2 hours, increasing the temperature to 25℃ for continuing the reaction for 4 hours, regulating the pH of a reaction product, extracting the reaction product with dichloroethane, and conducting separation to obtain 2-amino-5-chloro-pyridine. The yield of 2-amino-5-chloro-pyridine is up to 72%.

Synthesis Reference(s)

The Journal of Organic Chemistry, 41, p. 93, 1976 DOI: 10.1021/jo00863a020

Purification Methods

Recrystallise this base from pet ether. It sublimes at 50o/0.5mm. [Beilstein 22 II 332, 22/8 V 541.]