Famotidine Impurity 1(Famotidine EP Impurity A);Famotidine Related Compound A Dihydrochloride;Famotidine Impurity 1;Famotidine Dihydrochloride;ethyl 3-(((2-((diaminomethylene)amino)thiazol-4-yl)methyl)thio)propanoate;Famotidine EP Impurity A DiHCl;Propanimidamide,3-[[[2-[(aminoiminomethyl)amino]-4-thiazolyl]methyl]thio]-,dihydrochloride;Famotidine Impurity 1 Dihydrochloride (Famotidine EP Impurity A Dihydrochloride)