Agrochemical products herbicides

Agrochemical Products. The principal thiophene derivative in herbicidal protection, one of a range of sulfonylurea herbicides, is Harmony [79277-27-3] (Du Pont) (60), based on the intermediate methyl 3-aminothiophene-2-carboxylate (9). The product is characterized by a rapid biodegradabHity in the soil. Many other thiophene derivatives have been shown to have agrochemical activity, but few of these have been developed to the commercial level. 

Agrochemical Products. Hydrazones of vanillin have been shown to have a herbicidal action similar to that of 2,4-D, and the zinc salts of dithiovanillic acid. Made by the reaction of vanillin and ammonium polysulfide in alcohoHc hydrochloric acid, dithiovanillic acid is a vulcanization inhibitor. 5-Hydroxymerciirivanillin, 5- a cetoxym erci iri va n ill in, and 5-ch1oromercurivani11in have been prepared and found to have disinfectant properties. 

Heisey, R. M. 1999. Development of an allelopathic compound fromtree-of-heaven (Ailanthus altissima) as a natural product herbicide. In Cutler, H. G and Cutler, S. J. (Eds.), Biologically Active Natural Products Agrochemicals, CRC Press, Boca Raton, FL, 57-68... 

A fascinating example of enantioselective catalysis for agrochemicals is the production of a well-known herbicide of Novartis (formerly Ciba Geigy), metolachlor (Trade name Dual... 

Figure 11.3 is the representation of the case study that is used to demonstrate the performance of the proposed model it is taken from directly from Chapter 10. To facilitate understanding, this case study is described in some detail in this chapter. The plant, which constitutes 30% of production and consumes 55% of utility steam in the multinational agrochemical facility of choice, involves the manufacture of an herbicide. The saturated steam is produced from a coal fired boiler at 10 bar absolute pressure and 3 t/h, although it is only used at 4 bar in the chosen process. The process entails 3 consecutive chemical reactions which take place in 4 reactors. The first reaction, which uses water as a solvent, takes place in reactors R1 and R2. 

Vaughn SF (1999) Glucosinolates as natural herbicides. In Cutler HG, Cutler SJ (eds) Biologically active natural products agrochemicals. CRC Press, Boca Roton, FL81-91... 

In terms of applications, agrochemicals (synonyms pesticides, plant protection products) are subdivided into herbicides, about 45-50% insecticides, about 25-30% and fungicides, about 20%. Nematicides, rodenticides, and fumigants account for the remaining 10%. 

The top 20 agrochemicals in terms of sales dollars are compiled in Tables 11.6 and 11.7. The list shows both modern products requiring small dosages and old ones with high dosages. The former products require much smaller application rates, but also have much higher unit prices. The most expen-sive agrochemicals in terms of unit prices are the modern insecticides -cyhalothrin ( 768/kg) and Imidacloprid ( 461/kg) the cheapest ones are the old herbicides Atrazin ( 4.90/kg) and 2.4-D ( 5.80/kg). As shown in Table 11.8, the cheaper products are the simpler ones in terms of their chemical structure. 

The tnicroencapsululion of pesticides (qv) and herbicides active area of development that has produced several commercial products. The function of the microcapsules is to prolong activity while reducing mammalian toxicity, volatilization losses, phytotoxicity. environmental degradation, and movement in the soil. Ideally, encapsulation would also reduce the amount of agrochemical needed. 

In 1977, when the above review was presented and published, the history of the s-triazine herbicides was already 25 years old, with the first synthesis of these chemicals completed in 1952. The filing of the first basic triazine patent case in Switzerland was on August 16, 1954, and the first commercial products appeared on the market in 1956, following the approval of simazine for use in corn by federal authorities in Switzerland on December 3, 1956. Several other agrochemical companies started immediately to work with their own s-triazine variations, using other radicals or amino-functions on the s-triazine ring. This further research was also briefly reviewed in Knusli s 1977 paper. 

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