Organic Syntheses, Coll. Vol. 5, p.1055 (1973); Vol. 40, p.93 (1960).
Into a 1-l. round-bottomed three-necked flask fitted with a thermometer, a mechanical stirrer, and a dropping funnel
are placed 200 g. (1.05 moles) of p-toluenesulfonyl chloride
and 350 ml. of tetrahydrofuran (Note 1)
. The stirred mixture is cooled in an ice bath
to 10–15°; then a solution of hydrazine in water (135 ml. of 85% hydrazine hydrate, 2.22 moles
; (Note 2)
) is added at such a rate that the temperature is maintained between 10° and 20° (Note 3)
. Stirring is continued for 15 minutes after the addition is complete. The reaction mixture is transferred to a separatory funnel
. The lower layer is drawn off, and discarded. The upper tetrahydrofuran
layer is filtered with suction through a bed of Celite
to remove suspended particles and foreign matter (if any). The Celite
is washed with a little tetrahydrofuran
to remove any absorbed tosylhydrazide
. The clear, colorless filtrates are stirred vigorously during the slow addition of two volumes of distilled water. p-Toluenesulfonylhydrazide
separates as fluffy white crystalline needles (Note 4)
. The product is filtered through a Büchner funnel
; washed several times with distilled water, and air-dried. A yield of 175–185 g.
) is obtained; m.p. 109–110° (Note 5)
According to the submitters, commercial tetrahydrofuran (DuPont)
is washed several times with 40% aqueous sodium hydroxide
to remove peroxides and organic stabilizers and then dried over solid sodium hydroxide
. The clear supernatant liquid is used without further purification. This procedure is no longer regarded as being free from hazard as several serious accidents have occurred during attempts to purify tetrahydrofuran
in this fashion. The checkers used a good grade of commercially available tetrahydrofuran
taken from a freshly opened bottle (without washing or drying) as recommended in this volume (see p. 976
The submitters diluted 74 ml. of 95% hydrazine
with 74 ml. of water. The dilution of hydrazine
with water is exothermic. Hydrazine hydrate (50–100%)
may be substituted if the volume of water is adjusted so that the resulting solution contains 50% hydrazine
The addition is complete in 20–25 minutes.
Celite analytical filter aid, a product of the Johns-Manville Company, was used.
In some runs the checkers found it necessary to chill the mixture in the refrigerator for several hours or to stir the mixture in an ice bath
until the product crystalized.
The product may be contaminated with trace amounts of N,N'-di-p-toluenesulfonylhydrazide
. A more nearly pure product may be obtained by dissolving the crude product in hot methanol (4 ml. per gram of hydrazide)
, filtering through a bed of Celite, and reprecipitating the purified material by addition of 2 to 2.5 volumes of distilled water. This purification step is not necessary for most uses.
The submitters obtained the same yields with quantities as much as ten times those specified here.
has been found to be an exceptionally useful reagent in the synthesis of diazo compounds, olefins, and acetylenes and in the generation of diimide, carbenes, and carbenoid intermediates. Examples are too numerous to cite here; however, leading references may be found in Reagents for Organic Synthesis.6
This preparation is referenced from:
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