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love112358銀蟲 (初入文壇)
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[求助]
為什么我用三溴化吡啶做溴化無(wú)法重復(fù)實(shí)驗(yàn)?實(shí)驗(yàn)沒(méi)有重現(xiàn)性!
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| 求助。∥矣萌C花吡啶做酮的α-位的溴代反應(yīng),剛開(kāi)始成功過(guò)幾次,可是后來(lái)就再也沒(méi)有重復(fù)不出來(lái)這個(gè)結(jié)果了,怎么辦?麻煩高手幫忙解釋一下,感激不盡! |
鐵桿木蟲 (著名寫手)
roye
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試試這個(gè)。 Pyridinium tribromide (0.73 g, 2.29 mmol) was added to a solution of E (0.9 g. crude) in dry dichloromethane (30 mL) at 0℃ and the solution was warmed to room temperature and stirred for 1 h. A solution of sodium hydrogen carbonate (10%, 20 mL) was added and the aqueous layer extracted with dichloromethane (3×50 mL), washed with water, dried over sodium sulfate, and the solvent removed under reduced pressure. The crude product was purified by flash chromatography (CH2Cl2/MeOH 50:1) to give the product as a light-yellow slurry (0.55 g, 67%). 還有這個(gè)原料可能需要低溫干燥保存吧。。如果吸潮嚴(yán)重會(huì)影響反應(yīng)的,這種鎓的保質(zhì)期其實(shí)不長(zhǎng)。 |

銀蟲 (初入文壇)
鐵桿木蟲 (著名寫手)
roye

銀蟲 (初入文壇)
鐵桿木蟲 (著名寫手)
roye

銀蟲 (初入文壇)
鐵桿木蟲 (著名寫手)
roye

銀蟲 (初入文壇)
鐵桿木蟲 (著名寫手)
roye

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