10.1055/s-0034-1380748
The research aims to develop a method for synthesizing 2-(benzylthio)-4-(trifluoromethyl)thiazole-5-carboxylates using S-benzylisothiouronium halides as thiol equivalents. The purpose is to create a practical and safe synthetic route for these compounds, which are important in pharmaceuticals and agrochemicals, while avoiding the use of malodorous and toxic benzylthiols. The key chemicals used include 2-bromothiazole, various S-benzylisothiouronium halides, and ethylmagnesium bromide. The method involves a nucleophilic aromatic substitution reaction monitored by 19F NMR spectroscopy due to the presence of a trifluoromethyl group. The study concludes that the S-benzylisothiouronium halides are effective thiol surrogates, allowing for the synthesis of the target compounds in high yields (typically around 80%) and with good scalability. The method is also extendable to a one-pot process that includes ester hydrolysis, further simplifying the synthesis.
10.1016/S0040-4020(01)90973-1
The research focused on the synthesis and antifungal activity testing of camalexin and related phytoalexins, which are naturally occurring compounds produced by plants in response to fungal infections. The purpose of the study was to develop efficient short syntheses of camalexin and related 3-(2-thiazoyl)indoles to facilitate further testing of their antifungal activity. The researchers successfully synthesized camalexin and 6-methoxycamalexin using Grignard reactions involving indolylmagnesium halides and 2-bromothiazole. They also prepared other related compounds, including 5-methoxycamalexin and the oxazole analog. The antifungal activities of these compounds were examined against Cladosporium sp., with results indicating that camalexin and thiabendazole displayed significant antifungal activity at a 1 μg application level, while others showed activity at higher application levels. The study concluded that the basicity of the indole nitrogen may be important for antifungal activity, as compounds with modified nitrogen functionality showed reduced activity. Key chemicals used in the synthesis process included indole, methylmagnesium iodide, 2-bromothiazole, and various other substituted indoles and reagents for the preparation of intermediates and final products.
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