Dichloracetic acid

Further evidence for these a-helix ROA band assignments in the extended amide III region comes from the ROA spectrum of poly-L-alanine dissolved in a mixture of chloroform (70%) and dichloracetic acid (30%), known to promote a-helix formation (Fasman, 1987), which shows strong positive ROA bands at 1305 and 1341 cm-1 (unpublished results), and of the cv-helix forming alanine-rich peptide AK21 (sequence Ac-AAKAAAAKAAAAKAAAAKAGY-NHg) in aqueous solution which shows strong positive ROA bands at 1309 and 1344 cm-1 (Blanch et al., 2000). 

Wassermann (1965) carried out spectroscopic and conductimetric measurements of the interaction of azulene with trichloracetic and dichloracetic acids in benzene as the solvent. The basicity constant determined in these systems cannot, for the reasons explained in Section IVA, be compared with the o (-P = 1) values and with the basicities of... 

Although the mechanism of eqns (7) and (8) may be a reasonable one for the breakdown of [109], for some of the more reactive species, especially those derived from chloroacetic or dichloracetic acid, it may not be, as shown by the following considerations. For this mechanism to be valid the value of fc2 calculated from the relationship /cHO- = A fc2must be (i) less than the time constant for a molecular vibration (1012-1014s-1) fii) less than the value of based on the estimated Ka and the assumption that the ionization equilibrium (7) is diffusion controlled in the thermodynamically favourable direction, i.e. k1 = 10nM-1s-1. These two conditions are easily fulfilled with the hemiacetals and the less reactive hemiorthoesters derived from pinacol monoesters (see Table 15), but with the more reactive hemiorthoesters the calculated values of k2 lie close to or are greater than the cal-... 

Condensation, with sodium cy imwith sodium ethoxide, 35, 59... 

Hanson ML, Sibley PK, Mabury SA, Muir DCG, Solomon KR. 2003b. Field level evaluation and risk assessment of the toxicity of dichloracetic acid to the aquatic macrophytes Lemna gibba, Myriophyllum spicatum, and Myriophyllum sibericum. Ecotoxicol Environ Safety 55 46-63. 

DICHLOOR- TNYL)-DIMETHYL-FOSFAAT (DUTCH) see DGP900 DICHLOORVO pUTCH) see DGP900 DICHLORACETIC ACID see DELOOO DICHLORACETYL CHLORIDE see DEN400... 

In testing this relation Wildermann, amongst others, found for dichloracetic acid that the value of i derived... 

Complete conversion of nitric acid and potassium dichlor-acetate into potassium nitrate and dichloracetic acid would therefore be accompanied by an increase of volume of 20-046—i2 946= 7 100. The actual change of volume is given by a third experiment ... 

The ratio of sharing, or relative avidity, is therefore nitric acid dichloracetic acid = o-8 o-a = 4 1. 

Drop spread from dichloracetic acid on platinum sheet and air dried at 20°C in covered, greasefree container. 

P. Meyer [52] prepared substituted indigo blues from the corresponding substituted isatins. This process depends on the fact that the final products of the action of dichloracetic acid on amines in which the para position is occupied are substituted isatins. The first product of the action of dichloracetic acid on paratoluidine is a paratolylimide derivative of paramethylisatin, CieHigNjO, which decomposes on boiling with acids into paratoluidine and methylisatin, C9H7NO2. 

Further disconnection of (24) by 1,3-dicarbonyl methods (Chapter 19) gives aldehyde ester (25) as starting material. The aldehyde group will certainly need protection here and probably also during the Robinson annelation so available dichloracetic acid is used. 

Dichloracetic acid. See Dichloroacetic acid Dichloran. SeeDicloran... 

Synonyms Bichloracetic acid DCA Dichloracetic acid Dichlorethanoic acid 2,2-Dichloroacetic acid Dichloroethanoic acid... 

Berzelius (1848) later predicted acetic acids in which i or 2 equivalents (H ) of hydrogen in C H were replaced by chlorine (mono- and dichloracetic acids) it has never been tried if acetic acid could exhibit such a step-wise exchange, since the transformation of acetic acid by chlorine has always been pushed to the last term (trichloracetic acid). 

The last paper (S30) presented activity coefficients for the undissociated part of the following weak electrolyte acids benzoic, ortho toluylic, salicylic, ortho-nitrobenzoic, acetic, monochloracetic and dichloracetic acids. In a study of binary solutions of sodium and potassium acetate. RandaU. McBain and White (S26) found the ionic activity coefficients to be very close in value to the ionic activity coefficients for binary sodium and potassium chloride solutions. Consequently, in Randall and Failey s paper on the activity coefficients of the undissociated part of weak electrolytes, the activity coefficients of the monobasic acids in salt solutions oi varying concentrations were assumed to be equal to the activity coefficient of hydrochloric acid in the same or similar salt solution at the same concentration. This meant that ... 

Morpholine added to dichloracetic acid, excess morpholine then removed, the remaining mixture of morpholinium dimorpholinoacetate and morpholine hydrochloride dissolved in acetic acid containing ca. 10% water with ice-cooling, which is also maintained during the subsequent dropwise addition of the resulting mixture to coned. H2SO4 and 10-20%-oleum, the temp, of the bath raised towards the end of the reaction if necessary di-p-methoxyphenylacetic acid. Y 74%. F. e. and limitations s. A. Brault and M. Kerfanto, G. r. 258, 5465 (1964). 

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