Design, Synthesis, Structure, and Acaricidal/Insecticidal Activity of Novel Spirocyclic Tetronic Acid Derivatives Containing an Oxalyl Moiety

Abstract

A series of novel spirocyclic tetronic acid derivatives containing an oxalyl moiety was designed and synthesized via the key intermediate 3-(2,4,6-trimethyl)-2-oxo-1-oxaspiro[4.4]-decyl-3-en-4-ol. The target compounds were identified by (1)H NMR and elemental analysis or high-resolution mass spectrum (HRMS). The results of bioassays indicated that most of the target compounds possessed excellent acaricidal activities against carmine spider mite larvae and eggs. Especially, diisopropylamino oxalyl compound 7g and piperidine oxalyl compound 7h were 1.4- and 2.3-fold as high as the activities of commercial Spiromesifen, respectively, against spider mite eggs. Moreover, most of the target compounds exhibited insecticidal activities against Lepidoptera pest. Interestingly, compounds containing alkylamino-substituted oxalyl moiety showed obvious selectivity between spider mite larvae and eggs because the activities against spider mite eggs of 7g and 7h were 25-fold those against spider mite larvae, whereas Spiromesifen had no significant differences in these activities. This meant that the introduction of an oxalyl moiety to spirocyclic tetronic acid might lead to novel biological activity characteristics.

Rational design, synthesis and testing of novel tricyclic topoisomerase inhibitors for the treatment of bacterial infections part 1

“…Our synthetic route began with 2-bromo-3-methylaniline and introduction of cyclopropane moiety as an initial step using (1-ethoxycyclopropoxy)trimethylsilane 45 followed by borane reduction to give (3). Acylation with oxalyl chloride followed by intra-molecular Friedel-Crafts acylation, 46 using aluminium trichloride, gave isatin (4). This was then reacted with hydrogen peroxide to provide the anthranilic acid (5).…”

“…Intermediate (43) was then subject to standard Staudinger reduction conditions to form REDX05931. To synthesise REDX07473 and REDX07517, intermediate (42) was reduced with PPh 3 (Staudinger) to give the 2′-methylene amine intermediate (44), which was then BOC protected (45) and functionalised with an aryl pinicol ester (46). Finally, a BOC deprotection of intermediate(s) (46) with TFA in DCM furnished the desired products as TFA salts, which were then be neutralised/purified by column chromatography to elicit the final compounds as free bases (Scheme 6).…”

Design, synthesis and acaricidal/insecticidal activities of etoxazole analogues

“…The acaricidal activities against the larvae of spider mites of the title compounds 4a-y and the control compound etoxazole were evaluated by the leafdip method. 12,13 Mite-egg-infested leaves (choose the eggs which were laid at the same day) were kept at 25 1C for 4 days, and then they were cut and put on the test leaves as described above. After one day, the larvae were hatched and moved to the fresh leaves.…”

Support vector machine (SVM) classification model based rational design of novel tetronic acid derivatives as potent insecticidal and acaricidal agents

“…1), have been developed as good insecticides in modern agriculture for the control of a broad spectrum of insects, such as aphids, whiteies and psyllids, via the inhibition of acetyl-CoA carboxylase (ACCase). [3][4][5] So far, most of the efficient studies focused on C-4 and C-8 site of spirotetramat skeleton via application of traditional approaches, nevertheless, there are still some challenges needing to be addressed, such as low discovering efficacy and limited activities against mites, 6,7 promoting us to develop a novel series of tetronic acid derivatives with broader insecticidal spectrum, especially using more efficient method. [3][4][5] So far, most of the efficient studies focused on C-4 and C-8 site of spirotetramat skeleton via application of traditional approaches, nevertheless, there are still some challenges needing to be addressed, such as low discovering efficacy and limited activities against mites, 6,7 promoting us to develop a novel series of tetronic acid derivatives with broader insecticidal spectrum, especially using more efficient method.…”

“…1,2 Since the unique targeting characteristic, this kind of compounds are considered to be safer insecticides, rendering the scientists to perform extensively chemical optimization to explore the insecticide candidates with more potency and broader insecticidal spectrum. [3][4][5] So far, most of the efficient studies focused on C-4 and C-8 site of spirotetramat skeleton via application of traditional approaches, nevertheless, there are still some challenges needing to be addressed, such as low discovering efficacy and limited activities against mites, 6,7 promoting us to develop a novel series of tetronic acid derivatives with broader insecticidal spectrum, especially using more efficient method.…”