Synthesis The first total chemical synthesis of adrenaline was performed in 1904 by F. Stolz et al. pyrochatechol and chloro-acetylchloride react in the presence of phosphorchloridoxide to 3,4-dihydroxy- -chloracetophenone (Fries-rearrangement). After the conversion with methylamine, adrenalone will be reduced with sodiumamalgam to adrenaline. Severall other syntheses also use adrenalone as starting material. Biosynthesis 1: Phenylalanine-hydroxylase, 2: Tyrosine-hydroxylase, 3: Aromatic amino-acid decarboxylase, 4: Dopamine--hydroxylase, 5: Phenylethanolamine- N-methyl- transferase Five enzymes are involved in the pathway of the biosynthesis of adrenaline. The first enzyme is the iron containing phenylalanine-hydroxylase (also called phenylalanine-4-monooxygenase). The second enzyme, tyrosine-hydroxylase, contains iron, too, and catalyses the conversion of tyrosine to L--(3,4-dihydroxyphenyl)- -alanine (dopa). After decarboxylation of dopa to dopamine (aromatic amino-acid decarboxylase) the copper-containing enzyme dopamine- -hydroxylase converts dopamine to noradrenaline. The final enzyme noradrenaline-N-methyltransferase then methylates noradrenaline to adrenaline. The biosynthesis occurs in the adrenal medulla (see biologic function). Last change: 1999-04-12 Frank.Oellien@chemie.uni-erlangen.de