求助氫化鋁鋰還原酰胺的問(wèn)題
請(qǐng)教一下氫化鋁鋰還原酰胺的問(wèn)題，酰胺和氫化鋁鋰1:1.5還原，用了無(wú)水四氫呋喃作溶劑，反應(yīng)器也先用氮?dú)鉀_過(guò)，40度反應(yīng)3天。后面按水、15%氫氧化鈉水溶液、水的順序猝滅了反應(yīng)，反應(yīng)器里生成的氫氧化鋁結(jié)成了一大塊，于是又加了兩勺硫酸鈉，得到白色粘稠液體。離心、用無(wú)水硫酸鈉干燥、最后30度旋蒸所得液體，結(jié)構(gòu)不到30度液體就有氣泡生成，最后只剩下了一點(diǎn)白色粘稠物質(zhì)，沒(méi)有產(chǎn)物。
不知道大家有沒(méi)有什么好的建議，感激不盡！
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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，
感謝！
什么反應(yīng)要40度反應(yīng)3天再說(shuō)你淬滅前監(jiān)控反應(yīng)了嗎？沒(méi)有這個(gè)信息，根本無(wú)從推測(cè)是根本就沒(méi)生成產(chǎn)物還是產(chǎn)物在后處理時(shí)丟了或壞了。