2.2- Dichloropropionic acid

A mixture of 175 g. (1.11 moles) of methyl a, -dichloropropionate (p. 202) and 500 ml. of 20% aqueous hydrochloric acid is refluxed for 5 hours, after which it is cooled and filtered through glass wool. The filtrate is extracted with three 100-ml. portions of chloroform. After the extract has been dried over sodium sulfate, the chloroform and low-boiling components are removed by distillation under reduced pressure. The yield of crude product in the residue from the distillation is 105 g. (65%). Further purification by distillation gives a product boiling at 130-l33°/26 mm. and melting at 49-50°. 

By a similar procedure, hydrolysis of methyl a,/3-dibromopropionate (p. 202) with 48% hydrobromic acid solution gives a 72% yield of the acid, m.p. 59-60°. 

Hayes Jr, 3 Pesticides Studied in Man. pp 162-163. Baltimore, MD, Williams Wilkins, 1982 

Flessel P, Goldsmith JR, Kahn E, Wesolowski JJ Acute and possible long-term effects of 

3- dichloropropene, as possible cause of hematologic malignancies. Arch IntMed 144 1409-1411, 1984 

lARC Monographs on the Evaluation of the Carcinogenic Risks to Humans. Vol 41, Some halogenated hydrocarbons and pesticide exposures, pp 113-130. Lyon, International Agency for Research on Cancer, 1986 

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Glycerol -dichlorohydrin, 2.3-dichloro-propanol, CH2CI CHC1 CH2 0H. Colourless liquid, b.p. 182 C. Prepared by the chlorination of propenyl alcohol. Oxidized by nitric acid to 1,2-dichloropropionic acid. Reacts with NaOH to give epichlorohydrin. 

Dichloropropene,( 1 2,2-Dichloropropionic acid Dichlorotetrafluoro-ethane Dichlorvos ... 

Toxicology. 2,2-Dichloropropionic acid is expected to be an irritant of the eyes, skin, and respiratory tract. 

Dichloropropionic acid was not mutagenic in a variety of assays. The 2003 threshold limit value-time-weighted average (TLV-TWA) is Ippm (5.8mg/m ). 

US Department of Elealth and Eluman Services (NIOSH) Occupational safety and health guidelines for chemical hazards. Supplement IV-OHG (pub No. 95-121), pp 1-8. Occupational safety and health guideline for 2,2-dichloropropionic acid., Cincinnati, OEI, 1995... 

Two aliphatic acids possess, for grasses, many of the growth-distortion and toxicity effects associated with the synthetic auxins on dicotyledonous plants. Trichloroacetic acid and 2,2-dichloropropionic acid (dalapon), as the sodium salts, have been called grass "hormones or auxins, although Wilkinson184 could find no growth stimulation at low concentrations, and described dalapon as an antiauxin from its interference with indole-3-acetic acid effects. The herbicidal properties of trichloroacetate do not depend on its protein-denaturing ability, and those of 2,2-dichloropropionic acid involve, at least indirectly, the synthesis of pantothenic acid. 

Many other compounds have been included in studies on sucrose response. Most of these have been herbicides or enzyme poisons. None of the common herbicides had any positive effect on sucrose at rates up to that causing severe foliar injury. Earlier reports of response from 2-(2,4,5-trichlorophenoxy)propionic acid and 2,2-dichloropropionic acid could not be substantiated in British Guiana and Queensland. 27 Some compounds, such as 3-(p-chlorophenyl)-l,l-dimethylurea (monuron), (2,4-dichloro-phenoxy) acetic acid in soil, ethylenediaminetetraacetic acid, and leaf desiccants decreased sucrose and juice solids content. 20 Field trials with several chemicals in Trinidad showed enhanced sucrose at 14 to 28 days before harvest resulting from the application of 8 and 12 lb. (per acre) of... 

Pyruvic acid has been prepared from a, -dichloropropionic acid and from the corresponding dibromo add, by heating with... 

DichlorOpropionic acid, AB a,a-Dichlorotoluene, Aj6l a,2-0ichlorotoluene, AJ58 a,3-Dichlorotoluene, AJ59 a,U-Dichlorotoluene, Aj60... 

Dichloropropionic acid is a cheap reagent that can be linked to insoluble polymers either as an ester or an amide (1, Fig. 2). Although both chlorine atoms of this substrate were expected to show a slightly different reactivity toward nucleophiles, all attempts to displace these two leaving groups by two different nucleophiles failed. Regardless of the reaction conditions and the type of nucleophile used, both chlorine atoms were displaced by the first nucleophile. 

On the other hand, further experiments revealed that treatment of immobilized 2,3-dichloropropionic acid derivatives 1 with thiols afforded dithioethers 2, which were found to be unstable in the presence of bases, undergoing clean /3-elimination when treated with 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU) to yield acrylic acid derivatives 3. When this... 

The elimination/addition reaction already proceeded at room temperature when the dichloropropionic acid had been linked as an ester to the support, but required heating when an amide linkage had been chosen. When amines with low nucleophilicity were used, such as aniline or a-amino acid esters, higher reaction temperatures were also beneficial. Occasional by-products for this reaction sequence were acrylic acid derivatives or the corresponding hydrogenated products (2-thiopropionic acid derivatives). These by-products were usually formed when a very small excess of amine was used in the elimination/addition step. Both the thiols and the amines used in this reaction sequence could be polyfunctional, as illustrated by the examples sketched in Fig. 3. 

Fig. 3. Examples of products prepared by sequential nucleophilic substitution at support-bound 2,3-dichloropropionic acid derivatives. Purities were determined by HPLC monitoring at 214 nm.

To Wang resin (0.60 g, approx. 0.60 mmol) was added a solution of 2,3-dichloropropionic acid (0.87 g, 6.09 mmol) in dichloromethane (12 ml) followed by the addition of /V,/V -diisopropylcarbodnmide (0.48 ml, 3.07 mmol) and 4-dimethylaminopyridine (0.06 ml, 1 M in DMF, 0.06 mmol). The mixture was shaken at room temperature for 20 h, filtered, and the resin was washed with dichloromethane (3x6 ml). This resin was suspended in NMP (9.0 ml), treated with diisopropylethylamine (0.90 ml, 5.17 mmol) and thiophenol (0.60 ml, 5.84 mmol), and the resulting mixture was shaken at room temperature for 22 h. After filtration and washing with NMP (3x6 ml), the resin was suspended in NMP (9.0 ml), and piperidine (0.60 ml, 6.07 mmol) and DBU (0.90 ml, 6.02 mmol) were added. The mixture was shaken at room temperature for 22 h, filtered, and the resin was extensively washed with NMP, dichloromethane, and methanol, and resuspended in 1,2-dichloropropane. After shaking overnight at room temperature to remove traces of NMP the mixture was filtered, and the resin was suspended in a mixture of dichloromethane (4.5 ml) and trifluoroacetic acid (4.5 ml). After shaking at room temperature for 0.5 h the mixture was filtered, the resin was washed twice with dichloromethane, and the combined filtrates were concentrated. Crystallization of the residue from a mixture of ethyl acetate and heptane at —20° yielded the title compound... 

The technical assistance of Henrik Stephensen during the development of sequential nucleophilic substitutions at support-bound 2,3-dichloropropionic acid is gratefully acknowledged. Thanks are also extended to Marie Grimstrup, who optimized the synthesis of substituted benzamides. 

Dalapon (2,2-dichloropropionic acid), regulator Plants Ethyl ether extraction GC with ECD < 10 ppm [168]... 

Novel approach for optically pure alcohol from racemic compounds is the use of dehalogenases.24 For example, L-2-halo acid dehalogenase Pseudomonas putida was used for the synthesis of D-3-chlorolactic acid from racemic 2,3-dichloropropionic acid (Figure 23(a)).24ad The enzyme catalyzed hydrolytic release of halogen from 2-halocarboxylic acids and produces 2-hydroxy acids with inversion of the configuration. L-2-Halo acid dehalogenase acted on the L-isomer of 2-halo acids and produces D-2-hydroxy acid with an excellent enantioselectivity. 

Getzendaner s method [199] for determining Dalapon (2,2 dichloropropionic acids is applicable to plant tissues and body fluid and doubtlessly to water samples. The sample was extracted with ethyl ether and the residue was analysed by gas chromatography on a glass column (1.2mx 2mm) of 4% LAC-2R plus 0.5% of phosphoric acid on Gas Chrom S (60-80 mesh) at 100°C with nitrogen as carrier gas (85mL min-1) and electron capture detection. Recoveries of about 90% were obtained for lOppm of the herbicide. 

Chemical Name 2,2-dichloropropanoic acid 2,2-dichloropropionic acid a-dichloropropanoic acid a,a-dichloro-propionic acid... 

IUPAC name 2,2-dichloropropionic acid Molecular formula C3H4 CL2O2 Toxicity class USEPA II WHO III... 

Table V shows that Formulation C had a much lower viscosity than the other two and contained 20% w/v dalapon (the sodium salt of 2,2-dichloropropionic acid) in the aqueous phase. In the absence of dalapon, the viscosity of the emulsion was increased threefold, being similar to the viscosity of Formulations A and B. This effect is presumably caused by interaction between the salt and the emulsifier present. The presence of toxicant does not always reduce viscosity in fact, the presence of 20% w/v endrin in the oil phase of Formulation A will increase its viscosity slightly.

ACID a,a-DICHLOROPROPIONIC ACID DOWON DOWPON M GRAMEVIN KENAPON LIROPON PROPROP RADAPON REVENGE UNIPON... 

SYNS BASFAPON B DALAPON DALAPON SODIUM DALAPON SODIUM SALT 2,2-DICHLOROPROPIONIC ACID, SODIUM SALT DOWPON 2,2-DPA GRAMEVIN NATRIUMSALZ DER 2,2-DICHLORPROPIONSAEURE RADAPON SODIUM DALAPON SODIUM-a,a-DICHLOROPROP-lONATE SODIUM-2,2-DICHLOROPROPIONATE UNIPON... 

DICHLOROPROPIONIC ACID see DGI400 a-DICHLOROPROPIONIC ACID see DGI400 a,a-DICHLOROPROPIONIC ACID see DGI400... 

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