Cyclohexyl chloride, hydrolysis

B) Hydrolysis of Monohalides. (1) The following halides are used in this test n-butyl chloride, ec-butyl chloride, tert-butyl chloride, n-amyl chloride, cyclohexyl chloride, phenyl chloride chlorobenzene), and benzyl chloride. For the student s use the pure halides are placed in 25 ml bottles provided with droppers which serve also as stoppers to the bottle. The dropper is replaced in the bottle immediately after use. 

The same method has been applied to the spherically symmetrical chloro-substituent through equilibration of (16) and (17) in chloroform in the presence of aluminium chloride at temperatures between 210 and 334 K- Chloride ratios were estimated by g.l.c. after hydrolysis to the alcohols. The derived thermodynamic parameters are AH° = 0.68 0.03 kcal mol and A5° = 2.2 + 0.1 cal deg" mol" and the value of AS may be associated with the value indicated by symmetry considerations (see above) and suggests that for the isomerization (16) (17) AS° should approximate to zero. The present value for AH bears comparison with earlier studies with cyclohexyl chloride thus Reisse obtained —AH equal to 0.52kcalmol" with AS ss 0, and Jensen found — A.ff = 0.53 kcalmol" at — 80°C, both by the reliable peak area method. Calculations indicate —AH° to be 0.56 kcal mol for cyclohexyl chloride. 

Investigation of the mechanism of these reactions has suggested ways in which the yields can be improved. Acidic conditions (pH 2) will prevent Cannizzaro rearrangement of any glyoxal-type species and also serve to hydrolyse any Schiff bases which result from side reactions of aldehyde and amine. Conditions should be adjusted so that the rate of hydrolysis of linear products is equal to the rate of cyclocondensation, allowing accumulation of the imidazole products. From glyoxal, formaldehyde and ammonium chloride the yield of imidazole can be inereased to 85% by careful control of the conditions. With an appropriate alkylammonium chloride, 1-substituted imidazoles are also accessible (e.g. 1-methyl (56%), 1-isopropyl (46%), 1-cyclohexyl (49%), 1-n-butyl (55%), 1-t-butyl (25%)). The process may have some applications, but yields drop off with branched alkyl compounds [22 j. Imidazolium salts are also available under similar conditions when two molar equivalents of a primary alkylamine are used [23]. 

Piperazine-2,3,5-trione has been prepared from aminoacetamide and diethyl oxalate in methanolic sodium methoxide (365b). Oxanilic acid (PhNHCOCOOH) refluxed with thionyl chloride gave 1,4-diphenylpiperazinetetraone (identical with authentic material obtained by chromic acid oxidation of 1,4-diphenylpiperazine-2,5-dione) (1640). Hydrolysis of 3,3,5,5,6,6-hexachloro-4-cyclohexyl-I-phenyl-piperazin-2-one by heating at 100° with aqueous acetic acid gave l-cyclohexyl-4-phenylpiperazinetetraone (probably) (853). 

The j8-hydroxy esters obtained by Reformatzki syntheses are very readily dehydrated, so that water is often lost on distillation and hydrolysis then dehydration is completed by heating with acetic anhydride, acetyl chloride, potassium hydrogen sulfate, formic acid, or sulfuric acid. Depending on the nature of the substituents present on the /9-carbon atom, the products are oc,P- or /9,y-unsaturated acids or mixtures of both.43 In a few exceptional cases <%,/ - or /9,y-unsaturated acids can be obtained at will from /9-hydroxy acids by choice of a suitable dehydrating agent an example of this is (1-hydroxy-cyclohexyl)acetic acid (1) which, according to Wallach,44 is converted by potassium hydrogen sulfate or phosphorus(v) oxide into (1-cyclohexenyl)-acetic acid (2) but by acetic anhydride into the isomer, cyclohexylideneacetic acid (3) ... 

The alkylating agent can he a primary halide (chlorides react rather slowly) or a primary tosylate or dialkyl sulfate. In one example cyclohexyl bromide was used, but an extended reaction period was required. The paper also includes two mild conditions for the hydrolysis of (4) to the ketone (5). In one method the intermediates (4) are hydrolyzed by addition of 2 TV hydrochloric acid (overnight, 25°) to the reaction medium. In the other, triethylamine hydrofluoride in THF is added to the reaction mixture after addition of water, the organic products are extracted with methylene chloride. This solution is then treated with dilute NaOH. Triethylamine hydrofluoride presumably effects cleavage of... 

Half-lives for hydrolysis of Tc—Cl to Tc—OH have been determined for four so-called BATO complexes. These contain a semiencapsulating tris-dioxime ligand with a borate cap and the chloride ligand the technetium is seven-coordinate, (21), with Y = OH or Me and either R = Me or pairs of R comprise cyclohexyl rings. Rate constants lie in the range 19 to 1.2 x lO s" for the four complexes examined, at 20 to 37 There is also some very qualitative kinetic information on base hydrolysis and ligand exchange (Cl for Br and vice versa) in this type of complex. These reactions have half-lives of minutes in media such as aqueous acetonitrile. ... 

Cyclohexyl isocyanide (1 mmol) and / -fluorobenzoyl chloride (1 mmol) were heated neat for 1 h in a CEM microwave at 60 °C (50 W) and finally dissolved in toluene (2 mL). To this solution was added ZnCh in THE (0.1 mL of a 1 M solution) followed by the addition of phenyl tetrazole (1 mmol, 1 equiv). The reaction mixture was then heated overnight at 80 °C. Hydrolysis... 

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