Chloral hydrate elimination

Exposure occurs almost exclusively by vapor inhalation, which is followed by rapid absorption into the bloodstream. At concentrations of 150—186 ppm, 51—70% of the trichloroethylene inhaled is absorbed. MetaboHc breakdown occurs by oxidation to chloral hydrate [302-17-OJ, followed by reduction to trichloroethanol [115-20-8] part of which is further oxidized to trichloroacetic acid [76-03-9] (35—37). Absorbed trichloroethylene that is not metabolized is eventually eliminated through the lungs (38). The OSHA permissible exposure limit (PEL) eight-hour TWA concentration has been set at 50 ppm for eight-hour exposure (33). 

Chloral Hydrate. (An ethane derivative.) Chloral hydrate is one of the easiest drugs to make in this entire book. It is an effective hypnotic, that is rapidly absorbed from the stomach, and produces dulled sensoiy and motor functions, that last for 6 to 8 hours. The dose is from 250 mg to 1,500 mg. Chloral can be purchased at most any chemical supply house, eliminating the need for performing the first part of this synthesis. Chloral is not very suspicious (unless you re buying it by the 55 gallon drum), so you should have no trouble in making chloral hydrate directly from chloral. 

Disposition in the Body. Rapidly absorbed from the lungs about 50 to 65% of an inhaled dose is retained. Absorbed from the gastro-intestinal tract and through the skin. It is highly soluble in lipid-rich tissues, from which it is slowly released. Chloral hydrate is a transient metabolite which is further metabolised by reduction to trichloroethanol and oxidation to trichloroacetic acid. Trichloroethanol is mainly excreted as its glucuronide conjugate (urochloralic acid). Monochloroacetic acid is a minor metabolite. About 45% of an absorbed dose is excreted as urochloralic acid and about 30% as trichloroacetic acid in the urine in 3 weeks small amounts are eliminated in the faeces. About 16% is excreted unchanged in expired air. 

There is a definite need for a good, long-acting sedative which will have no cumulative properties—perhaps a long-acting chloral hydrate or an agent with slow onset of action but which is rapidly eliminated. 

C. Drugs or chemicals metabolized by alcohol dehydrogenase (eg, chloral hydrate, isopropyl alcohol) will also have impaired elimination. Fomepizole and ethanol mutually inhibit the metabolism of each other. 

Diaminouracil in 2%-sulfuric acid heated slowly to 90, an aq. soln. of chloral hydrate added, and stirring continued 15 min. at 90 2,4,6-trihydroxy-pteridine. Y 88%.— All three Gl-aloms are readily eliminated in this condensation. F. e. s. F. Bergmann, M. Tamari, and H. Ungar-Waron, Soc. 196A, 565. 

Dihydroxy alcohols (diols) and trihydroxy alcohols (triols) are viscous, hygroscopic, high boiling point liquids with a sweetish taste. Some of them are useful as solvents for pharmaceutical use. In the case of diols the two hydroxyl groups are usually attached to different carbon atoms. If the hydroxyl groups are attached to the same carbon an atom of water is eliminated to give a carbonyl compound (Fig. 5.5). There are exceptions to this for example, in the case of chloral hydrate the diol is stabilised by the electron-withdrawing chlorine atoms. 

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