Benzoyl phenyl urea

Chitin Synthesis Inhibitors. These are insect growth regulators that prevent the formation of the insect chitinous exoskeleton and thus produce a critical biochemical lesion during hatching, ecdysis, or pupation (44). These complex biochemical and physiological processes are unique to arthropods therefore, the benzoyl phenyl ureas are highly specific insecticides (44). 

Further studies revealed that in the first tests very coarse particles of these two derivatives had been used, while the testing of the other derivatives had been performed with fine particles. This focused attention for the first time on the great importance of particle size in the evaluation of the benzoyl-phenyl ureas. The series discussed included Du 19111 the first compound found, but the analyses indicated that other derivatives were more active. From two or three of the most active compounds PH 60-38 (ill) was chosen because it was found to be the one which could be synthetized most economically on an industrial scale. Consequently PH 6O-38 was taken for preliminary development both in the USA and in Europe. It is interesting to note that PH 6O-38 was one of the compounds retested after the QSAR studies. 

In addition to the effects of diflubenzuron on the chitinase and phenoloxidase levels, observed by Ishaaya and Casida (4 6), other biochemical influences of diflubenzuron and Du 19111 have been described in the literature (Table 9) A common feature of all these effects is their analysis one or more days after treatment. As any effects of these benzoyl-phenyl ureas become visible on the living insects only at the time of the next moult, when susceptible larvae die, investigators are prompted to search for defects up to a considerable time after application. In comparison with the very fast inhibition of chitin synthesis discussed above, in our opinion these studies can at the most indicate "secondary" effects. A considerable number of effects of this type can be expected to be found and published in the future. 

Benzoyl Phenyl Urea.—When this sodium salt of benzamide is treated with iodine two sodium atoms are lost from two molecules, a rearrangement occurs and the two molecules unite. 

The well-known insecticidal benzoyl phenyl ureas (BPUs), exemplified by diflubenzuron, are chitin biosynthesis disrupters, but at an uncharacterized site distinct from chitin synthase (2), Figure 1. The related bridge-cyclized oxazoline chemistries from DuPont and Yashima, represented by etoxazole, are also commercial or near-conunercial insecticides with the same mechanism of action (5), Figure 1. 

M.p. B.p. Picrate M.p. Acetyl deiiv. M.p. Benzoyl deriv. H.p. Benzene sulph. Onyl deriv. M.p. Toluene p-sulph> onyl deny. M.p. Phenyl urea deriv, M.p. 

Triflumuron (Alsystin , Baycidal ) [91,92], an /V-benzoyl-W-phenyl urea chitin synthase inhibitor commercialized by Bayer CropScience, is a broad spectrum insecticide that is active against chewing insects, as well as fleas and cockroaches. 

Over the past three decades, the N-benzoyl-N -phenyl ureas (BPUs) have been developed and used as commercial IGRs acting by inhibiting chitin biosynthesis... 

Other non-traditional preparations of 1,2,3-triazoles have been reported. The rearrangement in dioxane/water of (Z)-arylhydrazones of 5-amino-3-benzoyl-l,2,4-oxadiazole into (2-aryl-5-phenyl-27/-l,2,3-triazol-4-yl)ureas was investigated mechanistically in terms of substituents on different pathways <06JOC5616>. A general and efficient method for the preparation of 2,4-diary 1-1,2,3-triazoles 140 from a-hydroxyacetophenones 139 and arylhydrazines is reported <06SC2461>. 5-Alkylamino-] //-], 2,3-triazoles were obtained by base-mediated cleavage of cycloadducts of azides to cyclic ketene acetals <06S1943>. Oxidation of N-... 

The procedure may be adapted for the preparation of other acyl isocyanates (i.e., dichloroacetyl, trichloroacetyl, phenyl-acetyl, diphenylacetyl, benzoyl, etc) and is generally more convenient than the reaction of acid chlorides with silver cyan-ate3 4 Acyl isocyanates react with amines, alcohols, and mer-captans to yield acyl ureas, carbamates, and thiocarbamates. 

Amino-l,3,4-oxadiazoles form amides with acetic anhydride, benzoyl chloride and arenesulfonyl chlorides. With phenyl isocyanate, 5-substituted 2-amino-l,3,4-oxadiazoles yield urea derivatives (71a). Using an excess of phenyl isocyanate an isocyanate (71b) is produced, and with three equivalents of phenyl isocyanate l,3,4-oxadiazolo[3,2-a]-l,3,5-triazine-5,7-diones are obtained (Chapter 4.29) (74T221). 

The influence of protein denaturants (such as alcohols, urea and urea derivatives, and quaternary ammonium salts) on the stability of the compact-coil conformation of PMAA is also described. These protein denaturants, when added to aqueous solutions of PMAA, considerably limit the rate of the neutral hydrolysis of 1-benzoyl-3-phenyl-1,2,4-triazole. 

DFT calculations have probed electronic effects in the reaction of 2-arylhydrazono acetic acid with pyruvic acid to give (2Z)- and (2 )-3-aryl acrylic acids. Rearrangement of 11 (Z)-arylhydrazones of 5-amino-3-benzoyl-l,2,4-oxadiazole to give 2-aryl-5-phenyl-(2//-triazol-4-yl)ureas has been studied in toluene, with catalysis by TEA or piperidine, and compared to earlier results in more polar media. The kinetics of the acetophenone-phenylhydrazine reaction has been studied for a variety of solvents and ketone ring substituents. ... 

The acid-catalysed rearrangement of benzyl phenolic ethers to diphenylmethane compounds and the rates of rearrangement of (Z)-aryUiydrazones of 5-amino-3-benzoyl-l,2,4-oxadiazole into (2-aryl-5-phenyl-2H-l,2,3-triazol-4-yl)ureas have been reported. ... 

Kerstholt, R.P.V., Engberts, J.B.RN. and Blandamer, M.J., Kinetics of uncatalysed hydrolysis of l-benzoyl-3-phenyl-1,2,4-triazole and p-methoxyphenyl dichloroethanoate in aqueous solutions containing ureas, carboxamides, sulfonamides, sulfones and sulfoxides, /. Chem. Soc. Perkin Trans. 2, 1993, 49-51. 

ClflHi2N20Se, N-Phenyl-N -benzoylselenourea, 30B, 43 Cl5H12N6O9 f N,N Dimethyl N,N -di(2,4-dinitrophenyl)urea, 42B, 39 Cl5H1ftNftOs, N,N -Dimethyl-N,N -di(p-nitrophenyl)urea, 42B, 39 Cl7H17N5O6, 0-Benzoyl-N,N-dimethyl-N -(N-methyl-2,4-dinitroanilino)-isourea, 43B, 81 46B, 49 Cl7H20N2O5S2, N,N -Bis(tosylmethyl)urea, 44B, 52... 

---