Org. Synth. 1950, 30, 90
Submitted by Crosby U. Rogers and B. B. Corson1
Checked by Charles C. Price, Kenneth N. Campbell, and Robert P. Kane.
A mixture of 98 g. (1 mole) (Note 1) of cyclohexanone and 360 g. (6 moles) of acetic acid contained in a 1-l. three-necked round-bottomed flask equipped with a reflux condenser, a slip-sealed stirrer, and a dropping funnel is heated under reflux and stirred while 108 g. (1 mole) of phenylhydrazine is added during 1 hour. The mixture is heated under reflux for an additional hour and poured into a 1.5-l. beaker and stirred by hand (Note 2) while it solidifies. It is then cooled to about 5° and filtered with suction, the filtrate being cooled in ice and refiltered through the filter cake. The final filtrate is discarded. The filter cake is washed with 100 ml. of water and finally with 100 ml. of 75% ethanol. Each wash is allowed to soak into the filter cake before it is sucked dry. The crude solid is air-dried overnight (Note 3) and crystallized (Note 4) from 700 ml. of methanol after treatment with decolorizing carbon (Note 5); yield 120–135 g. of 1,2,3,4-tetrahydrocarbazole, m.p. 115–116° (Note 6). The mother liquor is concentrated to one-fourth of its original volume and yields an additional 10 g. of product (total yield 76–85%) (Note 7).
Equivalent amounts of cyclohexanone
(after suitable compensation for purity) and phenylhydrazine
are used. The cyclohexanone was about 90%
pure (analyzed by the procedure of Bryant and Smith2
). Instead of analyzing the ketone, it is safe to assume 90% purity.
The stirring should be sufficiently vigorous to prevent the formation of lumps.
The crude product requires 50–70 hours of air-drying to attain constant weight (145–155 g.
). It is preferable to crystallize the partially dried product.
The approximate solubility of 1,2,3,4-tetrahydrocarbazole
in 100 ml. of methanol
at 10°, 35°, and 55° is 5, 12, and 18 g. respectively.
A heated funnel is desirable for filtration of the hot solution, for the product separates on slight cooling.
The capillary melting point of tetrahydrocarbazole
ranges from 113° to 114° with slow heating and from 116° to 118° with fast heating.
may be prepared by the same general procedure. A solution of 172 ml. (2 moles) of concentrated hydrochloric acid
(sp. gr. 1.18) in 500 ml. of water is heated at the reflux temperature and stirred in a 2-l. three-necked round-bottomed flask
equipped with a reflux condenser, a slip-sealed stirrer, and a dropping funnel while 108 g. (1 mole) of phenylhydrazine
is added during 5 minutes. α-Tetralone (p. 898) (146 g.
, 1 mole or a correspondingly larger amount of material of 90% purity; see (Note 1)
) is added in a period of 1 hour, and the mixture is stirred and heated under reflux for an additional hour. The product is cooled to room temperature with stirring, and the beadlike product is filtered, washed as above, and crystallized from 2.3 l. of methanol
after treatment with decolorizing carbon
. The first crop amounts to 105–110 g.
and the second crop to 75–80 g.
, making the total yield 82–87%
; m.p. 163–164°
has been prepared from cyclohexanone phenylhydrazone
by the direct reaction of cyclohexanone
by the reaction of 2-chlorocyclohexanone
by heating 2-phenylcyclohexanone oxime
by the reaction of 2-hydroxycyclohexanone
by treatment of cyclohexanone phenylhydrazone
with a cation-exchange resin,14
and by the hydrogenation of carbazole
has been prepared from the phenylhydrazone of α-tetralone16
and by the direct reaction of α-tetralone
Chemical Abstracts Nomenclature (Collective Index Number);
phenylhydrazone of α-tetralone
hydrochloric acid (7647-01-0)
acetic acid (64-19-7)
decolorizing carbon (7782-42-5)
Carbazole, 1,2,3,4-tetrahydro- (942-01-8)
Copyright © 1921-, Organic Syntheses, Inc. All Rights Reserved