Org. Synth. 1955, 35, 83
DOI: 10.15227/orgsyn.035.0083
1-METHYL-3-PHENYLINDANE
[Indan, 1-methyl-3-phenyl-]
Submitted by Milton J. Rosen
1
Checked by R. T. Arnold and William K. Witsiepe.
1. Procedure
In a 500-ml. three-necked round-bottomed flask fitted with a mechanical stirrer and a reflux condenser are placed 50 g. (0.48 mole) of styrene (Note 1) and a previously cooled solution of 100 ml. of concentrated sulfuric acid in 150 ml. of water. The mixture is stirred vigorously (Note 2) and heated under reflux in an oil bath for approximately 4 hours.
Without interrupting stirring or heating, 50 ml. of concentrated sulfuric acid is added slowly through the condenser, and the mixture is stirred and heated for an additional 12 hours (Note 3).
The reaction mixture is cooled, cautiously poured into 250 ml. of cold water with stirring, and allowed to separate into layers. The upper hydrocarbon layer is removed, and the lower layer is extracted with three 50-ml. portions of ether. The combined ether extracts and hydrocarbon layer are washed successively with about 30 ml. each of a saturated solution of sodium bicarbonate, water, and a saturated solution of calcium chloride, and then dried over anhydrous calcium chloride. The ether is removed by distillation, and the product is distilled under reduced pressure. The yield of 1-methyl-3-phenylindane, b.p. 168–169°/16 mm. (Note 4), n20D 1.5811 ± 0.0005, is 38.5–40.5 g. (77–81%) (Note 5).
2. Notes
1.
Commercial
styrene, distilled from a
water bath at about 80–100 mm. pressure just before use, is employed.
2.
It is essential to use an efficient stirring device, capable of forming a dispersion of the
styrene in the acid layer.
3.
The
sulfuric acid is added in two portions in order to minimize higher-polymer formation.
24.
The product also distils at
150–151°/6.5 mm.5.
The submitter states that
α-methylstyrene can be converted to
1,1,3-trimethyl-3-phenylindane, b.p.
154–155°/8 mm.., m.p.
50.4–52.1°, by the same general procedure. The yield is
86–89% of the theoretical amount. The
1,1,3-trimethyl-3-phenylindane may be purified further by one recrystallization from three times its weight of
80% isopropyl alcohol. The yield of purified product, m.p.
51.8–52.3°, is
80–83% (based on the original weight of monomer used).
3. Discussion
1-Methyl-3-phenylindane has been prepared by the treatment of dimeric
styrene3 with aqueous
sulfuric acid, and by the hydrogenation of
1-methyl-3-phenyl-Δ2-indene.
4
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
1-methyl-3-phenyl-Δ2-indene
calcium chloride (10043-52-4)
sulfuric acid (7664-93-9)
ether (60-29-7)
sodium bicarbonate (144-55-8)
isopropyl alcohol (67-63-0)
styrene (100-42-5)
1-Methyl-3-phenylindane,
Indan, 1-methyl-3-phenyl- (6416-39-3)
α-methylstyrene (98-83-9)
1,1,3-trimethyl-3-phenylindane
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