This antidepressant is made from Chloridazon starting material.
The halogenation of 2-Butyne-1,4-diol [110-65-6] (1) with chlorine gives Mucochloric acid [87-56-9] (2). Treatment with Phenylhydrazine [100-63-0] (3) gives 1-Phenyl-4,5-dichloro-6-pyridazone [1698-53-9] (4). Addition of ammonia leads to Chloridazon [1698-60-8] (5). Catalytic hydrogenation yields 5-amino-2-phenylpyridazin-3-one [13589-77-0] (6). Alkylation with dimethyl sulfate completed the synthesis of Amezinium metisulfate (7).
References
^Araújo D, Caramona MM, Osswald W (June 1983). "On the mechanism of action of amezinium methylsulphate on the dog saphenous vein". European Journal of Pharmacology. 90 (2–3): 203–14. doi:10.1016/0014-2999(83)90238-8. PMID6873182.
^Lenke D, Gries J, Kretzschmar R (1981). "Pharmacology of amezinium, a novel antihypotensive drug. III. Studies on the mechanism of action". Arzneimittel-Forschung. 31 (9a): 1558–65. PMID7197970.
^Reicheneder F, Burger TF, König H, Kropp R, Lietz H, Thyes M, Wiersdorff WW (1981). "Amezinium. Synthesis and radioactive labelling". Arzneimittel-Forschung. 31 (9a): 1529–1533. PMID7197967.
^Beljean M, Pays M. "Heterocyclic hydrazines and hydrazones. II. Synthesis of hydrazino derivatives and of hydrazones in the thiazolo[4,5-d]pyridazin-7-ones". Bulletin de la Societe Chimique de France. 12 (2): 3324–3330.