# Design, Synthesis and Antifungal Activity of Novel Benzoylcarbamates Bearing a Pyridine Moiety
## 1 Introduction  
_Sclerotinia sclerotium_ and _Botrytis cinerea_ are two common plant pathogenic fungi that greatly influence the yield and quality of fruits and vegetables. The effective method for controlling such fungi is to employ chemical fungicides such as carbendazim, thiophanate-methyl, boscalid, and tebuconazole [1, 2]. However, the unreasonable use of fungicides has resulted in serious resistances in recent years. Therefore, developing novel and effective antifungal agents is critical to the control of plant diseases.  
Pyridine derivatives are important nitrogen-based heterocyclic compounds and are widely distributed in nature, e.g., nicotine, anabasine, pyridoxine, nicotinic acid, and nicotinamide. Many natural and synthetic pyridine derivatives show broad biological activity, including antifungal [3], anticancer [4], antivirus [5], anti-inflammatory [6], antitubercular [7], insecticidal [8], and herbicidal [9] activities. Additionally, pyridine is the bioisotere of benzene, but its electron density and hydrophobic constant are lower than those of benzene, thus pyridine derivatives often have high bioactivity and a notable systemic character [10]. Therefore, pyridine derivatives often serve as medicines and pesticides. Recently, two novel pyridine-based carbamate fungicides, picarbutrazox and pyribencarb, were respectively developed by Nippon Soda Co., Ltd. and Kumiai Chemical Industry Co., Ltd. [11, 12]. In addition, diethofencarb, tolprocarb, and benthiavalicarb-isopropyl are also carbamate fungicides [13, 14, 15]. These carbamate fungicides possess some unique properties such as strong selectivity, low toxicity, and environmental friendliness, and are commonly used to control manyplant diseases, e.g., _Sclerotinia sclerotorium_, _Botrytis cinerea_, _Plasmopara viticola_, and _Pltyophthora capsici_. On the other hand, some benzoyl carbamates exhibit high antifungal activity. For example, [PERSON] et al. designed and synthesized a series of aryl carbamic acid-5-aryl-2-furanmethyl esters [PERSON] et al. (2016), and three of them displayed notable antifungal activity against four fungi; the morphologic results suggested that the compound can disturb the cell wall formation of fungi.  
Inspired by the above findings, and based on our previous studies on the synthesis and bioactivity of pyridine-based compounds [PERSON] et al. (2016); [PERSON] et al. (2016), we herein chose tolprocarb and picarbutrazox as lead compounds, integrated benzoyl, carbamate, and pyridinyl moieties into one molecule by the method of active substructure combination, and designed and synthesized ten substituted benzoyl carbamates containing a pyridine ring. In the target molecule, benzoyl is directly linked to the carbamate moiety, whereas pyridinyl is linked to the carbamate via two carbon atoms, which can enhance the flexibility of the molecule. Thus, the affinity between the target molecule and fungus might be increased [PERSON] et al. (2016). Moreover, we also evaluated their antifungal activity against _Sclerotinia sclerotorium_ and _Botrytis cinerea_. Figure 1 shows the design strategy of the target compounds.