15686-71-2 38932-40-0 Cephalexin sodium salt EINECS 254-192-8 Sodium (6R-(6alpha,7beta(R*)))-7-(aminophenylacetamido)-3-methyl-8-oxo-5-thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylate