Anhydrous chloral

Liquids are occasionally purified by removing impurities as constant-boiling mixtures, or by shaking with concentrated sulphuric acid and subsequently separating the dried liquid from the acid the second method is therefore limited to liquids which are insoluble in, and chemically unaffected by, the strong acid e.g., benzene, anhydrous chloral). 

SYNS ACETALDEHYDE,TRICHLORO-(9CI) ANHYDROUS CHLORAL CHLOR. L, anhydrous, inhibited pOT) CLORALIO GRASEX RCRA WASTE NUMBER U034 TRICHLOROACETALDEHYDE... 

H3C)2N.CeH4.CHO, mw 149.19, N 9.39% Ifts, mp 74—75°, bp 176—77° at 17mm sol in hot w and in ale, eth AcOH. Can be prepd by mixing dimethylaniline, anhydrous chloral and phenol and allowing the mixt to stand. The phenol is removed by shaking with dil caustic soda and the residue dissolved in w HCl and crystallized (Ref 1) It was used in some military applications and its US Military specification and tests were described in Ref 3, which is now cancelled... 

Derivation By mixing dimethylaniline, anhydrous chloral, and phenol, and allowing the mixture to stand. The phenol is removed by shaking with dilute caustic soda, and the residue dissolved in water and hydrochloric acid and crystallized. 

Auisole and anhydrous chloral treated with vigorous stirring over a period of 1 hr. with small portions of A1C1S, and, after a total of 12 hrs. of vigorous stirring, allowed to stand for 10 hrs. —y l-trichloro-2,2-bis-(p-methoxyphenyl)ethane. Y 89.1%. 

Beilstein Handbook Reference) Acetaldehyde, trichloro- Anhydrous chloral BRN 0506422 CCRIS 852 Chloral Chloral, anhydrous, inhibited Cloralio EINECS 200-911-5 Grasex HSDB 2557 RCRA waste number U034 Trichloro-aoetaldehyde Trichloroethanal UN2075. Used in chemical synthesis and as a source of the drug chloral hydrate [302-17-0]. mp = -90° bp = 65.6° d = 1.273 soluble in H2O and organic solvents. Bristol-Myers Squibb Pharm. R D SmithKIine Beecham Pharm. 

Degradation of chloral hydrate occurs in the presence of an excess of free oxygen to form phosgene, CO2, and HCl, but only after a considerable lag-phase (52 days)227, unlike anhydrous chloral, which decomposes much more rapidly227. 

Anhydrous chloral has been shown to undergo autoxidation in air227 via both of the following reactions and possibly others. 

Common solvents Dimethyl sulfoxide, ethylene-diamine (hydrate and anhydrate), chloral (2)... 

A soln. of anhydrous chloral in anhydrous benzene added at room temp, to 4-chlorotestosterone, shaken until it dissolves and the product crystallizes 4 - chloro -17j - (1 - hydroxy -2,2,2- trichlorethoxy) androst -4- en -3- one. Y 9S%. R. Hiittenrauch, Arch. Pharm. 297, 124 (1964). 

Ethyl thioglycolate, anhydrous chloral, and a little coned. H2SO4 refluxed 6 hrs. in benzene 2-trichloromethyl-l,3-oxathiolan-5-one. Y ca. 90% —Mercaptals from other 0x0 compounds with HGl s. A. Liittringhaus and H. Prinzbach, A. 624, 79 (1959). 

Interesting results were obtained with proHne-tetrazole 22 in the reaction between ketones and chloral monohydrate or anhydrous chloral and water (100mol%). High yields and stereoselectivities were observed (Scheme 24.4). Addition of a higher amount of water increased the enantioselectivity of the reac-hon and decreased the diastereoselechvity. In contrast, the use of a catalytic amount of water (20 or 50mol%) disabled the catalyhc cycle (ca. 5% conversion). 

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