ByGraduateSchoolofPharmaceuticalSciences,FacultyofPharmaceuticalSciences,TheUniversityofTokyo [閱讀全文]
博文
(2022-05-23 09:57:37)
ByGraduateSchoolofPharmaceuticalSciences,FacultyofPharmaceuticalSciences,TheUniversityofTokyo [閱讀全文]
(2022-05-23 09:52:39)
磁子表麵通常塗有耐用的化學惰性聚四氟乙烯，其對絕大數反應並沒有影響。但當磁子持續使用數月甚至數年後，表麵微小的劃痕裏可就藏了不少難以清潔的痕量活性物質，特別是鈀，金，鉑，鈷，銅或鐵等金屬納米顆粒或微粒，這些活性微粒對一些反應具有催化效果。
研究人員對60個使用過的磁子進行觀察分類，這些磁子大部分都有損耗：有顏色變化的，有劃痕的，有凹[閱讀全文]
(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]
