V. K. Yadav, K. G. Babu
FULL PAPER
to the strong electron-withdrawal toward the aromatic ring
caused by the nitro function, resulting in less efficient (or
no) formation of the requisite vinyl cation.
Acknowledgments
The authors thank the Council of Scientific & Industrial Research,
Government of India, for financial support. KGB thanks CSIR,
and AG thanks UGC for the award of a Senior Research Fellow-
ship and a Junior Research Fellowship, respectively.
Conclusion
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[1b]
In summary, use of the AcCl/EtOH combination (8
equivalents each) brings about the transformation of olefins
into Markovnikov hydrochlorides in high yields with a con-
siderable shortening of reaction time in an operationally
convenient procedure (see Exp. Sect.). Chromatographic
purification is not generally necessary, as the product ob-
tained from removal of volatiles is pure enough to be used
directly in subsequent synthetic manoeuvres. This pro-
cedure is also effective for the transformation of nitriles into
imidates in excellent yields over timespans generally shorter
than reported previously (see Exp. Sect.). Since this method
generates HCl in situ, it obviates the dangerous nuisance of
corroded/frozen valves that is often experienced with lecture
bottles. The additional convenience of the clean transform-
ation of the initial solvent-cum-reactant into an inert and
easily removed solvent-cum-product is alchemical wizardry
at its best.[24]
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Experimental Section
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P. Boudjouk, B.-K. Kim, B.-H. Han, Synth. Commun. 1996,
General Procedure for the Hydrochlorination of Olefins: AcCl
(8 mmol, 0.57 mL) was added dropwise to a solution of olefin
(1 mmol) in dry EtOH (8 mmol, 0.47 mL). The reaction flask was
stoppered tightly and the stirring was continued at 30 °C. After the
reaction was complete by TLC, the unchanged AcCl and EtOH, if
any, and the EtOAc that had formed from the reaction of EtOH
with AcCl were removed under reduced pressure to obtain the
product.
26, 3479Ϫ3484.
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2778Ϫ2784.
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[14]
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[16]
[17]
[18]
[19]
[20]
General Procedure for the Preparation of Imidates: AcCl (8 mmol,
0.57 mL) was added to a stirred solution of a nitrile (1 mmol) and
an alcohol (12 mmol). The reaction flask was stoppered tightly and
the stirring was continued at 25 °C. After the reaction was complete
by TLC, the volatiles were removed under reduced pressure to iso-
late the imidate hydrochloride. Alternatively, the reaction mixture
was cooled to 0 °C and mixed slowly with saturated aqueous
NaHCO3 solution, until gas evolution had ceased. The product was
extracted into Et2O (3 ϫ 5 mL) and the organic solution was
washed with H2O (1 ϫ 5 mL) and brine (1 ϫ 5 mL) and concen-
trated under reduced pressure to obtain the imidate.
[21]
[22]
1
Supporting Information: H, 13C and analytical data on several of
[23]
[24]
G. W. Erickson, J. L. Fry, J. Org. Chem. 1987, 52, 462Ϫ464.
the compounds prepared in this study (see also the footnote on the
first page of this article).
An unknown referee.
Received August 19, 2004
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