1,1,3,3-Tetramethylguanidine80-70-6100 % similar N,N-Dimethylselenourea5117-16-842 % similar Tetrakis(dimethylamino)ethylene996-70-340 % similar Tetramethylthiourea2782-91-433 % similar Tetramethylurea632-22-433 % similar Metformin657-24-932 % similar Dimethylacetamide127-19-530 % similar