Bromides cyclohexylmagnesium

A 3-I. three-necked, round-bottom flask is fitted with a mechanical stirrer through a mercury seal, a reflux condenser and a i-l. separatory funnel. A mixture of 200 g. (r mole) of 2,3-dibromopropene (Org. Syn. 5, 49) and 200 cc. of dry ether is added. The flask is now cooled in an ice bath, the stirrer is started, and one molecular equivalent of cyclohexylmagnesium bromide, prepared from 31 g. of magnesium, 204 g. of cyclohexyl bromide and 400 cc. of dry ether (Note i) is added at such a rate that the mixture refluxes gently (Note 2). The addition takes about one-half to three-quarters of an hour. Two layers are formed and magnesium bromide may or may not separate. 

The preparation of cyclohexylmagnesium bromide is described on p. 22. The solution may be standardized by titrating against 0.5 N hydrochloric acid, and exactly one mole equivalent is used in the preparation. Five cubic centimeters of cyclohexylmagnesium bromide solution is slowly added to 20 cc. of water, an excess of the standard acid is added, and the excess acid titrated with sodium hydroxide. If 85 g. (3.5 moles) of magnesium, one liter of dry ether, and 571 g. of cyclohexyl bromide (3.5 moles) are used, a solution results which is about 2 molar. 

The reaction is instantaneous and is not stopped by moderate cooling. The cooling may be dispensed with and the cyclohexylmagnesium bromide added more slowly (two hours). 

Cyclohexyl-2-bromopropene-i has been made by the action of cyclohexylmagnesium bromide on 2,3-dibromopropcne.i Hull. soc. (him. (4) 211, 328 (i[Pg.21]

In much the same vein, the Mannich product from acetophenone with formaldehyde and pyrrolidine (44b) affords procyclidine (49) Dn reaction with cyclohexylmagnesium bromide. In an interesting variation, the ketone is first reacted with phenylmagnesium bromide. Catalytic hydrogenation of the carbinol (50) thus obtained iTin be stopped after the reduction of only one aromatic ring. ... 

The starting material was obtained by reacting ethyl formate with cyclohexylmagnesium bromide to give dicyclohexylcarbinol. That is oxidized to dicyclohexylketone and then reacted with a-picollne. 

Acetophenone, paraformaldehyde and diethylamine are first reacted to give CO-diethylamino-propiophenone. That is reacted with cyclohexylmagnesium bromide to give 3-diethylamino-1 -cyclohexyl-1 -phenylpropanol-1. 

Cyclohexylmagnesium bromide Perhexiline sulfate Cyclohexylmethylamine Bromhexine... 

Cyclohexyl chloride, 6, 24 Cyclohexylmagnesium bromide, 6, 20 Cyclohexylmagnesium chloride, 6, 24 3 Cyclohfxvi Propinf-i, 6, 26 Cyclopentanone, 5, 37 l Cystine, 5, 39... 

Enantiomer-selective polymerization of MBMA has also been attained by using the reaction products of chiral amine compounds, 168 and 169, with cyclohexylmagnesium bromide as initiator [242,243] and by using the aluminum porphyrin complex 170 in the presence of optically active aluminum alkoxide compounds 171a-e [244], In the latter systems, the enantiomer selection is based on enantiomer-selective coordination of the chiral aluminum compounds to MBMA as revealed by NMR analysis. With 171e as a catalyst, the ee of the unreacted monomer is 40% at 75% monomer conversion ratio in the polymerization at -70°C. 

As a secondary organomagnesium halide reagent, cyclohexylmagnesium bromide may also be useful for the synthesis of metal hydrides ... 

Soon after this publication, another report appeared (in 1932) on the (radical) reduction of benzophenone (again ) by cyclohexylmagnesium bromide and iodide [32]. 

Reaction of simple terminal alkynes normally leads to transmetallation [27]. However, substituted propargly alcohol reacts with cyclohexylmagnesium bromide to give, after rearrangement, the substituted allene [Eq. (7) 28.29]. 

Cyclohexylcyclohexanone, 180-181 Cyclohexyl fluoride, 627 N-Cyclohexylformamide, 382, 857, 878 Cyclohexylformyl peroxide, 57 Cyclohexylidenecyclohexylamine, 788 C clohexyl iodide, 94, 553, 873 C clohexyl isocyanide, 382, 857, 878 Cyclohexyl isothiocyanate, 181 Cyclohexylmagnesium bromide, 1232 Cyclohexyl methyl ether, 72-73 l-Cyclohexyl-3-(2-morpholinoethyl)-... 

---