Gravar-mail: Crystal structures of (E)-2-amino-4-methyl­sulfanyl-6-oxo-1-(1-phenyl­ethyl­idene­amino)-1,6-di­hydro­pyrimidine-5-carbo­nitrile and (E)-2-amino-4-methyl­sulfanyl-6-oxo-1-[1-(pyridin-2-yl)ethyl­idene­amino]-1,6-di­hydro­pyrimidine-5-carbo­nitrile