Dabigatran Etexilate Impurity H Catalogue D112428 CAS 1702936-92-2 M.W 350.38 M.F C19H18N4O3 Specifications FAQs ethyl 3-(1-methyl-N-(pyridin-2-yl)-1H-benzo[d]imidazole-5-carboxamido)propanoate