博文
(2022-05-23 09:50:35)
說起N.N-二甲基甲酰胺（DMF）大家一定很熟悉，因其良好的溶解性和較高的沸點，是有機合成中常用的有機溶劑之一，有萬能溶劑之稱。通常DMF在空氣中和加熱至沸點的溫度下都很穩定，但在反應體係中卻可能不那麽穩定了。
事實上，DMF在堿性和酸性條件下都可以分解產生二甲胺，這可以看成是一個酰胺的水解反應。純DMF是沒有氣味的，有時會在反應體係中聞到魚腥味，[閱讀全文]
(2022-05-21 07:23:54)
(2022-05-21 07:14:34)
Palladiumoncarbon(Pd/C)frequentlyigniteswhenitfirstcomesincontactwithmethanol(andtoalesserextent,anyflammableorganicsolvent)andassuchrepresentsasignificantsafetyrisk.TheseproceduresarerecommendedwheneverPd/Cisusedinconjunctionwithhydrogengas. Hydrogenationusingaballoon: 1)Evacuatethereactionvessel(thisshouldhaveatleasttwoopenings)andbackfillwithaninertgas(nitrogenorargo...[閱讀全文]
(2022-05-21 07:12:37)
Hazards:Hydrogenationreactionsposeasignificantfirehazardduetotheuseofflammablereagentsandsolvents.Suchreagentsincludepalladiumoncarbon(Pd/C),whichishighlyflammableandcanignitesolventsandhydrogen.Itisespeciallydangerousafterhavingbeenusedforthehydrogenation.Thepresenceofhydrogengasincreasestheriskofexplosion.閱讀全文]
(2022-05-21 07:11:12)
Donotpouranychemicalsintothesink.[閱讀全文]
(2022-05-21 07:10:15)
ThebehaviourofaminsonTLCsometimeisweird.Evenonepurecompound,anaminecanshowmorethanonespotwhenaneutraleluentsystemisemployed.Inthissituation,abasiceluentsystembyaddingbasesuchammoniaortriethylaminewillredresstheproblem.[閱讀全文]
(2022-05-21 06:49:43)
nonereaction,mCPBAhasbeenusedforconvertingonealkenetooneepoxide.Afterthereaction,theexcessmeta-Chloroperoxybenzoicacidshouldnotbepouredintotheorganicwastebarrel.[閱讀全文]
(2022-05-21 06:48:46)
Formonitoronereaction,TLCshouldbethefirstconsideration.DonotrelayonNMRformonitoringonereaction.[閱讀全文]
(2022-05-21 06:47:43)
Hastebringsnosuccess;hastemakeswaste;morehaste,lessspeed.[閱讀全文]
(2022-05-21 06:46:16)
Don'tMakeAnyDecisionWhenYouAreAngry.
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