Chloral hydrate, structure

Chirality center, 292 detection of, 292-293 Eischer projections and, 975-978 R,S configuration of, 297-300 Chitin, structure of, 1002 Chloral hydrate, structure of, 707 Chloramphenicol, structure of, 304 Chlorine, reaction with alkanes, 91-92,335-338 reaction with alkenes, 215-218 reaction with alkynes, 262-263 reaction with aromatic compounds, 550 Chloro group, directing effect of, 567-568... 

When dissolved in water, trichloroacetaldehyde (chloral, CCJ3CHO) exists primarily as chloral hydrate, CCl CHCOH, better known as "knockout drops." Show the structure of chloral hydrate. 

Colorimetric procedures used In steroid assays are often subject to drug Interference. In the determination of 17-Ketosterolds by the Zimmerman reaction, drugs with the 17-Keto basic structure such as ascorbic acid, morphine and reserplne will cause Increased values. In the determination of 17,21 -dlhydroxysterolds by the Porter-Sllber reaction the dlhydroxy-acetone chain Is the reactive unit. Drugs like meprobamate, chloral hydrate, chloropromazlne and potassium Iodide will Interfere with this reaction and cause elevated values. In the colorimetric determination of vanlllylmandellc acid (VMA) by a dlazo reaction, drugs like methocarbamol and methyl dopa cause... 

Our Form II has two uncommon features. In the first place it contains two hydroxyl groups attached to the same carbon but we have that in chloral hydrate. In the second place there is an ethylene oxide oxygen linkage. This might be called an alpha lactone with the water not split off. This formation of a ring structure is believed to account for the reversal of the sign of rotation. It is well known that the formation of the lactide from lactic acid, while not a lactone formation in the same... 

The determination of 17-ketosteroids is most often determined in the clinical laboratory by the Zimmerman reaction, in which the ether-extracted material is allowed to react with m-nitroaniline to yield a colored product. Thus, any compound with the 17-keto basic structure such as reserpine, morphine, ascorbic acid, or their metabolites will interfere. The Porter-Silber reaction used in the determination of 17,21-dihydroxysteroids is also not specific, and the reaction requires a di-hydroxyacetone side chain. Paraldehyde, chloral hydrate, meprobromate, and potassium iodide have been found to interfere, and patients should be maintained free of these drugs for 24-48 hours before the urine collection (Bll). 

CNS effects Because of dichloralphenazone s structural similarity to chloral hydrate, there is a potential for CNS depressant effects. 

The chemical structures of some older and less commonly used sedative-hypnotics, including several barbiturates, are shown in Figure 22-3. Glutethimide and meprobamate are of distinctive chemical structure but are practically equivalent to barbiturates in their pharmacologic effects. They are rarely used. The sedative-hypnotic class also includes compounds of simpler chemical structure, including ethanol (see Chapter 23) and chloral hydrate. 

Write an electron-dot structure for chloral hydrate, also known in detective novels as "knockout drops."... 

The induced dipole moment depends on the electric field strength and the structure of the molecule. Charge-induced dipole interactions occur between a charged ion and polarized molecules. A molecule possessing conjugated double bonds is readily polarized. Examples of solutions due to the dipole-induced dipole interaction are benzene in methanol, chloral hydrate in CC14, and phenol in mineral oil. 

Chloral.—Chloral, or tri-chlor acet-aldehyde, was first prepared by Liebig in 1832 by the chlorination of alcohol as above. It may also be obtained by the direct action of chlorine upon acet-aldehyde. It is an oily liquid with a sweet suffocating odor. It boils at 97.7°. It does not mix with water but on boiling with water it forms a hydrated compound which crystallizes in large clear crystals, readily soluble in water. This is known as chloral hydrate. The structure of chloral hydrate is probably that of an addition product, viz., a, chlorinated di-hydroxy alcohol. In this compound we have an exception to the general rule that two hydroxyl groups can not be linked to the same carbon atom. 

PROBLEM 17.5 Chloral is one of the common names for trichloroethanal. A solution of chloral in water is called chloral hydrate this material has featured prominently in countless detective stories as the notorious "Mickey Finn" knockout drops. Write a structural formula for chloral hydrate. 

Acetaldehyde can be converted into the sedative chloral hydrate (the Mickey Finn or knockout drops often mentioned in detective stories). In the first step of the reaction that forms chloral hydrate, acetaldehyde, CH3CHO, changes to its isomer, CH2CHOH. Draw a reasonable Lewis structures for each of these isomers. 

Meprobamate is an antianxiety agent. It produces CNS depressant action at multiple sites, including thalamic and limbic systems. It is indicated in the management of anxiety (see Table 9). Many drugs with diverse structures have been used for their sedative-hypnotic properties, including paraldehyde (introduced before the barbiturates), chloral hydrate, ethchlorvynol, glutethimide, methyprylon, ethinamate, and meprobamate (introduced just before the benzodiazepines). 

Chloral, CI3C—CH=0, reacts with water to form the sedative and hypnotic agent chloral hydrate, CI3C—CH(OH)2. Draw Lewis structures for these substances, and describe the change in molecular shape, if any, that occurs around each of the carbon atoms during the reaction. 

The use of trichloroacetaldehyde is also to be particularly noted. Although reactions between this aldehyde and various dialkyl hydrogenphosphonates have been report- 269,274,294,295 it is the dimethyl ester of (l-hydroxy-2,2,2-trichloroethyl)phosphonic acid which has received particular attention, and which has been studied widely from the structural point of view in the light of its commercial importance as the powerful insecticide dipterex (also known as trichlorphon and chlorophos). Polyfluoroalkyl esters of the related alkyl(l-hydroxy-2,2,2-trichloroethyl)phosphinic acids have been prepared by the unusual combination of chloral hydrate and the bis(polyfluoroalkyl) alkylphosphonite ester ... 

Chloral is an oily liquid, which has a penetrating odor it boils at 97° and has the specific gravity 1.512 at It reacts with water with the evolution of heat, and forms chloral hydrate, a compound which crystallizes well from water and melts at 57°. Chloral hydrate is much used as a soporific. The formula usually assigned to chloral hydrate is CCl3.CH(OH)2. There is in this case the same uncertainty as to structure as in the case of glyoxylic acid (321). Chloral hydrate shows most of the reactions of aldehydes it reduces an ammoniacal solution of silver nitrate, and reacts with hydroxylamine. It does not, however, affect Schiff s reagent (188). Concentrated sulphuric acid converts it into chloral. 

Examination of the spectral results is limited to regions that correspond to singly bonded structural features. The correct structural formula for chloral hydrate follows. You can see that aU of the bonds in the molecule are single bonds. 

An understanding of the infrared spectrum of chloral hydrate should be approached from a study of the spectrum of chloral, which has been described in some detail in the literature 1 2,3. Chloral hydrate has been shown to have a gem-diol structure by Raman spectra and by N.M.R.5 Comparison of the infrared (mull) spectra of the compound and of its deuterated analogl71 indicates that the two OH groups are not equal. This is confirmed by solution spectra sl8,23,168,171 and Ogawa23 suggests that chloral hydrate exists in solution in an equilibrium state, which may be represented as follows -... 

Near infrared studies on a solution of chloral hydrate show the existence of a labile equilibrium between the gem-diol and a dimolecular 1 1 complex of the aldehyde and water. It is thought that the gem-diol structure results from the electronic effect of the halogens transmitted through the molecule, rather than from intramolecular hydrogen bonding between the halogens and the hydroxyl hydrogens. 

The crystal and molecular structure of chloral hydrate has been investigated by x-ray diffraction23 > 119,120,121,312 crystal struc-... 

Schill9 suggests that in a melt of chloral hydrate several hydrates of different structures may exist. By calculation froiri Schill s figures, an approx, heat of solution for chloral hydrate ir water is -0.78Kcal/m.ol. Measurements of the heat of dilution of chloral hydrate aqueous solutions have been made95. No Nernst temperature coefficient is found for these solutions. 

The crystal and molecular structure of the (1 1) molecular complex of chloral hydrate and bromodiazepam has been determined by x-ray diffraction studies312. 

The compound chloral hydrate, known in detective stories as knockout drops, is composed of 14.52% C, 1.83% H, 64.30% Cl, and 19.35% O by mass and has a molar mass of 165.4 g/mol. (a) What is the empirical formula of this substance (b) What is the molecular formula of this substance (c) Draw the Lewis structure of the molecule, assuming that the Cl atoms bond to a single C atom and that there are a C—C bond and two C—O bonds in the compound. 

Other addition reactions of aldehydes oeeur. Water, for example, adds to the earbonyl of trichloroacetaldehyde to form chloral hydrate, a strong hypnotic and sedative known as knock-out drops or (when mixed with alcohol) a Mickey Finn. Complete the reaction by drawing the structural formula of chloral hydrate ... 

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