殺ダニ剤ヘキシチアゾクスの開発

抄録

Hexythiazox, trans-5- (4-chlorophenyl) -N- cyclohexyl- 4- methyl- 2- oxothiazolidine- 3- carboxamide is a new potent miticide discovered and developed by Nippon Soda Co., Ltd. This compound shows broad miticidal spectrum and excellent ovicidal, larvicidal and nymphcidal actions.
The discovery of a lead compound originated in the studies of fungicidal thiazolotriazines which showed weak miticidal activity, and the structural modifications of them led to discover the 2-oxazolidinones as the second lead of miticides. As the result of the lead optimization, we developed 2-thiazolidinone derivatives among which hexythiazox was selected as the best compound.
In the synthesis of hexythiazox, stereoselective processes were required because the trans configuration of 4-methyl and 5-p-chlorophenyl groups is essential for the biological activity. We have investigated the stereoselective synthesis of the trans-2-thiazolidinones, and established a novel method via erythro-aminoalcohol as a key intermediate. Furthermore, some improvements in the synthesis of the erythro-aminoalcohol from p-chloropropiophenone have also contributed to the success in the industrial production of hexythiazox.