Organic Syntheses, CV 6, 555
2,3-DIPHENYLVINYLENE SULFONE
Submitted by Louis A. Carpino
1 and Louis V. McAdams III.
Checked by Timothy P. Higgs and Ronald Breslow.
1. Procedure
Caution!
Benzene has been identified as a carcinogen; OSHA has issued emergency standards on its use. All procedures involving
benzene should be carried out in a
well-ventilated hood, and glove protection is required.
To a magnetically stirred solution of
6.36 g. (0.0157 mole) of crude α,α'-dibromodibenzyl sulfone (m.p.
135–150°;
Org. Synth., Coll. Vol. 6, 403 (1988)) in
40 ml. of dichloromethane contained in a
100-ml., round-bottomed flask fitted with a reflux condenser there is added in one portion
5.05 g. (0.0500 mole) of triethylamine. The solution is heated at reflux with stirring for 3 hours (Note
1), filtered, and the precipitate washed with
5 ml. of cold (0°) dichloromethane. The combined
dichloromethane solution is washed with two
20-ml. portions of 3 N hydrochloric acid followed by one 10-ml. portion of water. Removal of the solvent by distillation from a
water bath at 30° with the aid of a
water aspirator gives
3.0 g. (
80%) of the
vinylene sulfone as a tan solid, m.p.
116–126° (dec.). The crude solid is washed with
5 ml. of cold (0°) ethanol and recrystallized from about
10 ml. of benzene, yielding
2.4–2.5 g. (
63–67%) of the pure sulfone as tiny, snow-white needles, m.p.
123–126° (dec.) (Note
2).
2. Notes
2. The submitters obtained a similar percent yield on ten times the scale.
3. Discussion
2,3-Diphenylvinylene sulfone has been prepared by dehydrohalogenation of either
α,α'-dibromodibenzyl sulfone2 3 or
α,α'-dichlorodibenzyl sulfone,
4 as well as by oxidation of
2,3-diphenylvinylene sulfoxide.
5 The procedure described here illustrates a general technique for the synthesis of diarylvinylene sulfones and has been extended to a number of substituted derivatives.
5,6 Aliphatic derivatives have been synthesized in other ways.
3,7,8 The vinylene sulfones are a group of compounds of considerable theoretical interest.
2,3,9 10 11 12 13
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