Phenylacetylene ethylmagnesium bromide

Phenylacetylene added to ethylmagnesium bromide in anhydrous ether, stirred 2-3 hrs. at gentle reflux, a dry ethereal soln. of benzhydroximic chloride added dropwise at 0° during 1 hr. with stirring, which is continued for 10 min. -> product. Y 70%, F. e. s. Z. Hamlet, M. Rampersad, and D. J. Shearing, Tetrah. Let. 1970, 2101. 

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). 

Triethylamine added at 60° to Na previously dispersed at 110° under dry Ng in xylene containing a little oleic acid, then phenylacetylene in xylene added drop-wise at a rate to keep the temp, at ca. 60°, after the exothermic reaction has ceased warmed 0.5 hr. at the same temp., bis-(p-methoxyphenyl)carbodiimide in xylene added dropwise at room temp, during 10 min., finally dimethyl sulfoxide in xylene added with water-cooling, and the product isolated after 0.5 hr. -> N,N -bis-(p-methoxyphenyl)phenylpropiolamidine. Y 65%. - No significant reaction occurs in the absence of dimethyl sulfoxide. F. e., also with ethylmagnesium bromide instead of Na, s. H. Fujita et al.. Bull. Chem. Soc. Japan 45, 1846 (1972). 

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). 

Scheme 5 Reaction of phenylacetylene with ethylmagnesium bromide, then with phenyl azide followed by the reaction with benzaldehyde...

A soln. of phenylacetylene in a little anhydrous tetrahydrofuran added with stirring to a soln. of ethylmagnesium bromide in the same solvent, refluxed for some time, cooled, a soln. of a-chlorobenzalphenylhydrazine in tetrahydrofuran added with stirring, refluxed 0.5 hr., and allowed to stand for 12 hrs. 1,3,5-triphenylpyrazole. Y 94%. F. e. s. P. Griinanger and M. R. Langella, G. 90, 229 (1960). 

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