Ethylmagnesium bromide 1-phenyl

Methyl-2-phenyl-5-oxazolone (22) reacts with excess phenyl-magnesiuin bromide to give 2-benzainido-1,1-diphenyl-1-propanoP (23). With excess ethylmagnesium bromide, 22 forms a dimer, N,N -... 

Phenyl-2-butanol has a methyl group, an ethyl group, and a phenyl group (—Cgl ) attached to the alcohol carbon atom. Thus, the possibilities arc addition of ethylmagnesium bromide to acetophenone, addition of methylmagnesium bromide to propiophenone, and addition of phenylmagnesimn bromide to 2-butanone. 

We can use a ketone containing an ethyl groups and a phenyl group (ethyl phenyl ketone) and allow it to react with ethylmagnesium bromide ... 

When the ethylene oxide contains an aromatic substituent, as in styrene oxide, there is a significant tendency for preliminary isomerization to oocur. Thus, treatment of styrene oxide with methyl-magnesium bromide or ethylmagnesium bromide yields 1 -phenyl-2-propauol and l-phemyJ-2-butanol respectively1 83 (Eq. 841). 

Thiazole and benzothiazole exchange the C-2 hydrogen for lithium or magnesium when treated with an ethereal solution of phenyl- or butyl-lithium at -60 °C or ethylmagnesium bromide at 0 °C then at 25 °C (Scheme 31). When the 2-position of thiazole is occupied by a methyl group, the reaction of butyl-lithium at low temperature (-100 °C) affords three independent lithio salts (54, 55 and 56 Scheme 32) in the approximate ratio 52 3 45. As the temperature is increased, the 2-lithiomethyl derivative (54), which is less stable than the 5-lithio isomer (56), decomposes up to +5 °C at which point it has almost entirely disappeared. 

A solution of 2-(pyrazol-l-yl)phenylmagnesium bromide in THF (350 ml) is prepared by metallation of 1-phenylpyrazole (86.5 g, 0.6 mol) by ethylmagnesium bromide [9] and stirred and maintained at 25-30° as a solution of benzonitrile (51.6 g, 0.5 mol) in THF (150 ml) is added rapidly. The mixture is heated under reflux for 6 h, cooled, and poured into a solution of ammonium chloride (120 g) in water (1 litre). The solution is extracted with ether, and the ether phase is extracted with 2 m hydrochloric acid (total 600 ml). (Evaporation of the ether phase then leaves 1-phenylpyrazole (40 g)). The acid extract is (without filtration from the crystals which precipitate) treated with 10 m sodium hydroxide (300 ml) and extracted with ether. Evaporation of the extract gives phenyl 2-(pyrazol-l-yl)phenyl ketimine (99 g, 80% based on benzonitrile), m.p. 106-107°. 

The Grignard reaction of benzaldehyde with ethylmagnesium bromide in diethyl ether in the presence of molar amounts of (J , J )-TADDOL as a chiral additive leads predominantly to (S)-l-phenyl-l-propanol, while the same reaction carried out in tetra-hydrofuran gives mostly the corresponding (i )-alcohol according to Eq. (5-154a) [852]. TADDOL is the acronym for tetraaryl-l,3-fi ioxolane-4,5-fiSmethano/, which reacts with... 

Not only lithium-derived organometallic compounds have proved to be suitable reagents for generating a new C —P bond Grignard and cadmium compounds have also found some applications, but they are not so widespread. For example, tris(pentafluorophenyl)phosphane (26) and bromobis(pentafluorophenyl)phosphane (27) both give ethy bis(pentafluoro-phenyl)phosphane (28) on reaction with ethylmagnesium bromide.12... 

Rundle and co-workers performed X-ray diffraction studies on solid phenyl-magnesium bromide dietherate and on ethylmagnesium bromide dietherate, which they obtained by cooling ordinary ethereal Grignard solutions until the... 

The effect of phenyl substitution on the rate of Grignard addition to IV-benzylidinetmiline has been examined. The reaction rate in ether for ethylmagnesium bromide conforms to r = it[R 2Mg-MgX2][Schiff base]. A four-centered reaction mechanism (Scheme 3) has been suggested. ... 

Dehydration with phenyl isocyanate afforded a more homogeneous product (still a mixture of isomers) of higher vitamin A activity. The reaction was carried out by treating a solution of 33 g. of (1) in 150 ml. of purified phenyl isocyanate with 2 ml. of 1.5M ethylmagnesium bromide as catalyst and stirring the mixture at 95° for 3 hrs., during which time diphenylurea continuously precipitated (in the absence of catalyst no significant amount of diphenylurea was observed). 

Alkyl and arylmagnesium halides react with 2-methylquinoxaline by addition of one mole of reactant to the 3,4-bond. After hydrolysis the 2-alkyl- or 2-aryl-l,2-dihydro-3-methylquinoxalines (52) are obtained. When ethylmagnesium bromide is used a dimeric by-product (53) is also isolatedReaction of 2,3-dimethylquinoxaline with benzonitrile and lithium amide gives l-amino-l-phenyl-2-(3-methyl-2-quinoxalinyl)-ethylene (54). The mono- and dilithium salts of 2,3-dimethylquinoxaline have been generated from the quinoxaline by reaction with one or two equivalents of lithium diisopropylamide (LiNPr, respectively. These salts have been reacted with a variety of electrophilic reagents such as alkyl halides, aryl ketones, esters, and nitriles. " ... 

Acetals have been employed to derive 1,1-bis(2-hydroxyphenyl)alkanes. In this way propanal diethylacetal added to phenoxymagnesium bromide, prepared from phenol and ethylmagnesium bromide, gave 1,1-bis(2-hydroxy-phenyl)propane in 70% yield after refluxing for 24 hours (ref. 10). The enolic character of the phenoxy compound favours nucleophilic 2-substitution. 

Consider an example using an ester. When an excess of ethylmagnesium bromide is added to methyl benzoate, the first equivalent adds and methoxide is expelled, giving propiophenone. Addition of a second equivalent, followed by protonation, gives a tertiary alcohol 3-phenyl-3-pentanol. 

Epoxy-l,3,5-cyclooctatriene added dropwise with ice-cooling to a soln. of propynylmagnesium bromide prepared from propyne and ethylmagnesium bromide in abs. ether, stirred 2 hrs. at room temp, and 1 hr. under reflux -> l-(2,4,6-cycloheptatrien-l-yl)-2-butyn-l-ol (Y 75%) dissolved in dimethylformamide, ice-cooled, treated dropwise with a soln. of SOClg in dimethylformamide, and stirred 1 hr. at room temp. l-phenyl-l-penten-3-yne (Y 87%). F. e. s. J. Hambredit, H. Straub, and E. Muller, B. 107, 2985 (1974). 

A soln. of 2.4 eqs. LiBr in THE added slowly to 1.2 eqs. Cul at —60, after 5 min a soln. of 2.4 eqs. ethylmagnesium bromide in THE added dropwise, after stirring for 1 h 1 eq. phenylacetylene in 20 7 /HMPA added, followed after 5 min by 2.4 eqs. trimethylchlorosilane in HMPA, the mixture slowly warmed to room temp., stirred for 5 h then poured into satd. NH4CI soln. containing a little NaCN (E)-2-phenyl-l-(trimethylsilyl)-l-butene. Y 85%. LiBr suppressed deprotonation. F.e. and electrophilic substitution reactions s. S.-S.P. Chou et al., J. Org. Chem. 54, 868-72 (1989). 

Benzonitrile added to a soln. of 3 moles ethylmagnesium bromide in toluene, and hydrolyzed -> 3-phenyl-3-aminopentane. Y 60%. F. e. s. G. Alvernhe and A. Laurent, Tetrah. Let. 1973, 1057. 

A soln. of phenylacetylene in anhydrous tetrahydrofuran added dropwise during 0.5 hr. to a soln. of ethylmagnesium bromide prepared from ethyl bromide and Mg in the same solvent, stirred 2 hrs. at 50, then a soln. of piperidino-methyl butyl ether in the same solvent added, and refluxed 3 hrs. with stirring l-phenyl-3-piperidino-l-propyne. Y 76%. F. e., also from cyclic compounds, s. I. Iwai and Y. Yura, Chem. Pharm. Bull. 11, 1049 (1963). 

---