The structural unit of substituted pyridazine is present in many biologically active compounds and a lot of research is now focused on the synthesis of novel pyridazine-based building blocks and combinatorial libraries.1 The substructure of pyridazine is found in a few natural compounds.2 Thus, Azamerone 13 (Figure 1) produced by a marine-derived bacterium is the most recently discovered representative of natural products containing pyridazine ring. Besides the natural occurrence, the pyridazine substructure is present in many agrochemicals, medications, and technologically relevant compounds. The first pyridazine-based herbicide Chloridazone 2, shown in Figure 1, put on the market as early as in 1964, is still used for the cultivation of different sorts of beet. In contrast to the agrochemical applications, the use of pyridazines as medications has started relatively recently. Till date, there have been 8 approved and 34 investigational pyridazine-based drugs of different pharmacological actions.4 For example, Minaprine 3 is a marketed pyridazine-derived psychotropic drug which has proved to be effective in the treatment of various depressive states. Another commercial pyridazine-containing drug Hydralazine 4 is an efficient antihypertensive agent. Recently pyridazine derivatives were shown to be potent amyloid inhibitors.5 In materials science pyridazines are used as versatile ligands for metal cations.6
Figure 1. Examples of natural products, agrochemicals, and synthetic drugs containing the pyridazine fragment
The full list of the functionalized pyridazines offered by Life Chemicals can be obtained upon request at firstname.lastname@example.org. Please see some representative compounds below:
- For recent works, see: (a) Fan, Z.; Pan, Z.; Huang, L.; Cheng, J. J. Org. Chem. 2019, 84, 4236–4245. (b) Dey, R.; Kumar, P.; Banerjee, P. J. Org. Chem. 2018, 83 (10), 5438–5449. (c)Li, H.; Sun, Z.; Wu, W.; Wang, X.; Zhang, M.; Lu, X.; Zhong, W.; Dai, D. Org. Lett. 2018, 20, 7186–7191.
- Maes, B. U. W.; Lemiére in Comprehensive Heterocyclic Chemistry III, Eds. Katritzky, A. R.; Ramsden, C. A.; Scriven, E. F. V.; Taylor, R. J. K. Pergamon, Oxford, 2008. Vol. 8, p. 3.
- Cho, J. Y.; Kwon, H. C.; Williams, P. G.; Jensen, P. R.; Fenical, W. Org. Lett. 2006, 8, 2471.
- www.drugbank.ca; accessed in April 2019.
- Kalhor, H. R.; Khodadadi, A. N. Chem. Res. Toxicol. 2018, 31, 1092–1104.
- Solntsev, P. V.; Sieler, J.; Chernega, A. N.; Howard, J. A. K.; Gelbrich, T.; Domasevitch, K. V. J. Chem. Soc., Dalton Trans. 2004, 695.