Water → 1,2,3,3-Tetramethylindoline

Beteiligte Stoffe

Reaktionsschritte

To a stirred solution of 3.46 g of 1,3,3-trimethyl-2-methyleneindoline (VIII, R2 =R8 =R9 =Me) in 50 ml methanol was added at room temperature in three portions at about five-minute intervals a total of 1.14 g of sodium borohydride (conveniently, as three 7/16-inch pellets, a commercially available form). The initial deep red color of the solution gradually changed to a light orange during the reaction. The mixture was then diluted first with 20 ml of ethyl ether, and then with 50 ml of water. The ether layer was separated, and the lower aqueous layer was again extracted with ether. The combined ether layers were washed with 10% aqueous sodium hydroxide solution and then water, and dried over anhydrous magnesium sulfate. Removal of solvent from the filtered extracts left 3.10 g (88.6%) of an orange oil. This oil was distilled in vacuum to give 2.52 g (72.0% of the theoretical amount of 3.50 g) of pale yellow oil boiling at 80°-81° C. at 2.3 mm Hg pressure.

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