1-Methylindene → HCID 86754446, compound

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Reaction Steps

12.4 ml of LiBu 2.5 M in hexane are added, at room temperature, to an ether solution of 4.2 g (0.032 moles) of 1-methylindene in 100 ml of ethyl ether. The mixture is left under stirring for 3 hours, then 3.8 g (0.022 moles) of 2-isopropylidene-2,4,5,6,7,8-hexahydroazulene are added at -70° C. The temperature is left to rise and the mixture is left under stirring for 48 hours. The reaction mixture is hydrolyzed in water and extracted with ethyl ether which after evaporation provides a solid which is purified on a silica gel column using petroleum ether as eluant. 4.5 g (0.0148 moles) of 2-[1-(3-methyl-1H-Inden-1-yl) -1-methyl-ethyl]-1,4,5,6,7,8-hexahydroazulene are obtained which are dissolved in 200 ml of ethyl ether, to which 18.8 ml of LiMe 1.6 M in ether ethyl are added and the mixture is left under stirring for a night. A slightly yellow precipitate is formed. The mixture is cooled to -70° C. and 3.51 g (0.015 moles) of zirconium tetrachloride are added. The temperature is brought to room temperature and the mass tends to take on a dark brownish-yellow coloring. The mixture is filtered, washed with ethyl ether which tends to become yellow, and is then extracted with methylene chloride (2×100 ml). The solution is brought to a small volume and 20 ml of ethyl ether are then added. A solid precipitates which is filtered, washed with ether and hexane and then dried. 1.0 g of complex are obtained. After two days large orange crystals separate from the yellow ether mother liquor, which when filtered and washed with hexane give 2.1 g of pure complex for a total of 3.1 g (45% yield calculated on the ligand used). 1H NMR (CDCl3, δ ppm rel. TMS): 7.55 (d, 2H); 7.25 (m, 1H); 6.95 (m, 1H); 5.65 (s, 1H); 5.43 (d, 1H); 2.8-2.5 (m, 4H); 2.45 (s, 3H); 1.9-1.6 (m, 7H); 1.40 (m, 2H).

Provenance & Evidence