Tetramethylene diamine (putrescine): Crude oil → propylene → acrylonitrile → succinonitrile → tetramethylene diamine Hexamethylene diamine (HMD): Crude oil → butadiene → adiponitrile → hexamethylene diamine 1,9-diaminononane: Crude oil → butadiene → 7-octen-1-al → 1,9-nonanedial → 1,9-diaminononane[57] 2-methyl pentamethylene diamine: a by product of HMD production Trimethyl Hexamethylene diamine (TMD): Crude oil → propylene → acetone → isophorone → TMD m-xylylene diamine (MXD): Crude oil → m-xylene → isophthalic acid → isophthalonitrile → m-xylylene diamine[58] 1,5-pentanediamine (cadaverine) (PMD): starch (e.g. cassava) → glucose → lysine → PMD.[59]