求助氢化铝锂还原酰胺的问题？TAKE THIS AS AN EXAMPLE: An oven-dried, 3-L, three-necked flask equipped with a mechanical stirrer, a Friedrich condenser, and a nitrogen-inlet tube is flushed with nitrogen, and then charged with a suspension of lithium aluminum hydride (47.9 g, 1.26 mol) in 1200 mL of tetrahydrofuran (THF) (Note 1). The mixture is cooled (10°C, ice bath) and L-valine (100 g, 0.85 mol) is added in portions over a 30-min period from a 200-mL round-bottomed flask connected to the reaction flask via a flexible plastic sleeve so as not to produce too vigorous an evolution of hydrogen (Note 2). After the addition is complete, the plastic sleeve is replaced by a stopper, the ice bath is removed, and the reaction mixture is warmed to room temperature and then refluxed for 16 hr. The reaction mixture is then cooled again (10°C, ice bath) and diluted with ethyl ether (1000 mL) (Note 3). The reaction is quenched over a 30-min period with water (47 mL) (Caution! See (Note 4), aqueous 15% sodium hydroxide (47 mL, over 20 min), and water (141 mL, over 30 min). The solution is stirred for 30 min and the white precipitate is filtered. The filter cake is washed with ethyl ether (3 × 150 mL) and the organic filtrates are combined, dried with anhydrous sodium sulfate, and concentrated under reduced pressure查看更多
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