Methanol → HCID 57723635, compound

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Reaction Steps

In a 250 ml round bottom flask 19.2 g (63 mmol) 4,7-Dibromo-2-methyl-indan-1-one were dissolved in 70 ml of toluene at 50° C. Then 2.63 g (1.1 eq.) sodium borohydride were added. At 50° C. 11 ml (4.3 eq.) methanol were added dropwise over a period of 30 min. Stirring was continued at 50° C. for 3 h (complete conversion) and then 50 ml water and 50 ml of 2M H2SO4 were added. The aqueous phase was extracted 2 times with 100 ml toluene. The combined organic layers were washed with 50 ml 2M H2SO4 and 50 ml of a sodium chloride solution, dried over magnesium sulfate and the solvent was removed in vacuo. 200 ml toluene and 200 mg p-toluene sulfonic acid were added and the solution was heated on a Dean-Stark-trap for 90 min. 50 ml of a saturated sodium bicarbonate solution were added. The aqueous layer was extracted 2 times with 50 ml toluene each. The combined organic layers were washed with 50 ml of a saturated sodium bicarbonate solution and 50 ml of a sodium chloride solution, dried over magnesium sulfate and the solvent was removed in vacuo to yield 17.8 g (62 mmol, 98%) of the desired indene as a slightly brown oil. 1H-NMR (500 MHz, CDCl3): δ=7.48, 7.35 (2×d, 2H, aromatic), 6.49 (s, 1H, indenyl-C═CH), 3.32 (s, 2H, benzylic), 2.12 (2, 3H, CH3) ppm.

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