Herbicides chlorinated aliphatic acids

Figure 2 shows a simplified process flow diagram for halogenated aliphatic acid production facilities [8]. Halogenated aliphatic acids include chlorinated aliphatic acids and their salts, for example, TCA, Dalapon, and Fenac herbicides. Chlorinated aliphatic acids can be prepared by nitric acid oxidation of chloral (TCA) or by direct chlorination of the acid. The acids can be sold as mono- or dichloro acids, or neutralized to an aqueous solution with caustic soda. The neutralized solution is generally fed to a dryer from which the powdered product is packaged. 

Foy, C.L. (1976) The chlorinated aliphatic acid. In Herbicides Chemistry, Degradation and Mode of Action, Marcel Dekker, New York. 

Eight of the nine compounds are chlorinated phenoxyadds dalapon is a chlorinated aliphatic acid. The positive ion thermospray mass spectra of these pesticides are summarized in Table I. The base peak in all cases is the (M+NH4)+ ion for 2,4-DB the (M+H) ion is present No ions were detected for dalapon. Since the protonated molecule is present for 2,4-DB this compound has the highest apparent proton affinity among these herbicides. 

Acidic compounds This group of pesticides comprises different families of compounds with herbicidal action, including substituted phenols, chlorinated aliphatic acids, chlorophenoxy alkanoic acids, and substituted benzoic acids, which all possess carboxyl or phenolic functional groups capable of ionization in aqueous media to yield anionic species [90,96-99]. The following is a summary ... 

Gas chromatography has been applied to the determination of a wide range of organic compounds in trade effluents including the following types of compounds which are reviewed in Table 15.15 aromatic hydrocarbons, carboxylic acids aldehydes, non ionic surfactants (alkyl ethoxylated type) phenols monosaccharides chlorinated aliphatics and haloforms polychlorobiphenyls chlorlignosulphonates aliphatic and aromatic amines benzidine chloroanilines chloronitroanilines nitrocompounds nitrosamines dimethylformamide diethanolamine nitriloacetic acid pyridine pyridazinones substituted pyrrolidones alkyl hydantoins alkyl sulphides dialkyl suphides dithiocaibamate insecticides triazine herbicides and miscellaneous organic compounds. 

Preferred Name Dalapon sodium salt Synonyms Basfapon Basfapon B Basfapon/ Basfapon N BH Dalapon Basinex Crisapon Dalapon 85 Ded-Weed Devipon 2,2-Dicloro-propionic acid a-Dichloropropionic acid a,a-Dichloropropionic acid Dowpon Dowpon M Gramevin Kenapon Kyselina Liropon Proprop Radapon Revenge Unipon Chemical/Pharmaceutical/Other Class Chlorinated aliphatic herbicide Chemical Structure ... 

In non-saline sediments aliphatic and polyaromatic hydrocarbons, phthalate esters carboxylic acids, uronic acid aldoses chloroaliphatics haloaromatics chlorophenols chloroanisoles polychlorobiphenyls polychlorodibenzo-p-dioxins poychlorodibenzofurans various organosulphur compounds, chlorinated insecticides, organophosphorus insecticides mixtures of organic compounds triazine herbicides arsenic and organic compounds of mercury and tin. 

In the chemical industry chlorine is used for the production of various chemical compounds, such as hydrochloric acid, hypochlorites, chlorates, bleaching powder, aluminium chloride, corrosive sublimate, cupric chloride, carbon tetrachloride, tin recovery from used cans, sulphuryl chloride, for extraction of bromine from Stassfurt waste liquors, etc. In the organic chemical industry it is used for the chlorination of aliphatic and cyclic organic compounds, for the preparation of medicaments, the manufacture of plastics, insecticides, fungicides and herbicides. Monochloracetic acid, ethylene chlorhydrine, chloral, chlor-... 

The chlorophenoxyalkanoic acids constitute yet another economically important group of halogenated aromatic hydrocarbons. They are widely used as herbicides to control dicotyledonous weeds. The most important of them are 2,4-D and its propionic and butyric acid homologs, 4-chloro> 2-methylphenoxyacetic acid (MCPA), and 2,4,5>trichlorophenoxyacetic add (2,4,5-T). In all the cases studied, aerobic biodegradation proceeds by removal of the aliphatic side chain with the formation of the corresponding chlorinated phenoL Thus, formation of 2,4 chlorophenol from both 2,4-D and 4-(2,4-dichlorophenoxy)-butyric acid, 4-chloro-o-cresol from MCPA, and 2,4,5-trichlorophenol from 2,4,5-T has been... 

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