An efficient synthesis is described for hexabromoanthracenes 3 and 4 by direct bromination of 9,10-dibromoanthrecene 2. Whereas base-induced elimination of hexabromide 3 with t-BuOK gave 2,3,9,10-tetrabromoanthracene 5, the reaction of hexabromide 4 with DBU afforded 1,3,9,10-tetrabromoanthracene 6 as the sole product. Tetrabromide 5 was also obtained by aromatization of 1,4-dinitroxy-2,3,9,10-tetrabromo-1,2,3,4-tetrahydroanthracene 17. Efficient and convenient synthetic routes are described for the preparation of dinotroxy 17, dimethoxy 23, and dihydroxides 18 and 19 with silver-induced substitution of hexabromides 3 and 4. The hydroxy compounds 19 and 18 were converted to diepoxide 20 and monoepoxide 21, respectively, with sodium methoxide. Base-promoted aromatization of dimethoxide 23 afforded dibromomonomethoxides 26 and 27. Bromoanthracenes and isomeric arene oxides constitute valuable precursors for the preparation of functionalized substituted anthracene derivatives that are difficult to prepare by other routes.
This study investigated Pseudomonas putida biotype B as a potential biological control agent of Tetranychus urticae. The bacteria were isolated from greenhouse soil from Carsamba, Turkey. The experiment was carried out in a completely randomized plot design under laboratory conditions. For this purpose, spraying and dipping applications of a suspension of P. putida biotype B (10(8)-10(9) colony forming units/ml) were applied to newly emerged, copulated females. Dead mite and egg counts were started on the 3rd day after treatments, and observations were continued daily until all the mites had died and egg hatching had finished. Both types of bacterial application significantly reduced total egg numbers and egg hatching, compared to their respective controls. Bacterial spraying was significantly more effective than dipping-the spray application demonstrated 100% efficacy and resulted in the fewest viable eggs. The results of this study indicated that P. putida biotype B has a strong efficacy in causing mortality in T. urticae.
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