Metformin alternative synthesis #Kani

From: https://en.wikipedia.org/wiki/Metformin

"The usual synthesis of metformin, originally described in 1922 and reproduced in multiple later patents and publications, involves the one-pot reaction of dimethylamine hydrochloride and 2-cyanoguanidine over heat.[98][99]

According to the procedure described in the 1975 Aron patent,[100] and the Pharmaceutical Manufacturing Encyclopedia,[101] equimolar amounts of dimethylamine and 2-cyanoguanidine are dissolved in toluene with cooling to make a concentrated solution, and an equimolar amount of hydrogen chloride is slowly added. The mixture begins to boil on its own, and after cooling, metformin hydrochloride precipitates with a 96% yield."