Methylethylenethiourea13431-10-2100 % similar 1,3-Dimethyl-2-imidazolidinethione13461-16-040 % similar 1-Methylpiperazin-2-one59702-07-735 % similar 1-Methyl-3-oxopiperazine34770-60-031 % similar Dazomet533-74-430 % similar