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3含氮有机化合物含氮有机化合物主要包括硝基化合物,胺类化合物,重氮和偶氮化合物等.3.1硝基化合物RNOONOONOO++3.1.1芳香族硝基化合物的性质(1)还原NO2NNONNHNHNNHOHNOEtOHNH4ClNH2FeHClNH2As2O3,NaOHFe+NaOHZn+NaOHZn+H2OZn+H2O氧化偶氮苯偶氮苯氢化偶氮苯N-苯基羟胺亚硝基苯苯胺Zn(或Sn或Fe)+HCl(2)芳环上的亲核取代反应NO2ClNO2OHClNO2OHNO21.NaOH,130℃2.H3O+1.NaOH,135℃2.H3O+ClNO2OHNO21.NaOH,100℃2.H3O+NO2NO2ClNO2NO2OCH2CH3NO2NO2Et3NFNO2OCH3NO2CH3OHClNO2NH2NO2ClNO2NO2NHCH3NO2NO2+CH3CH2OH20℃+CH3OK25℃+NH3+CH3NH23.1.2脂肪族硝基化合物的性质(1)α-氢的酸性RCH2NOORCHNOHOCH3NO2CH3CH2NO2(CH3)2CHNO2pKa10.28.57.8(2)与羰基化合物的反应CHOCHCHNO2+CH3NO225℃戊胺β-硝基苯乙烯3.2胺氨分子中一个,两个或三个氢原子被烃基取代所生成的化合物分别称为伯胺(一级胺)、仲胺(二级胺)和叔胺(三级胺)。铵盐分子中四个氢原子都被烃基取代生成的化合物称为季铵盐。有些胺类化合物因其特殊的生理活性,与人类的生命活动及健康密切相关。NNCH2H3CNH2NSH3CCH2CH2OHCl-+维生素B1CH2CHNH2CH3NCOC2H5CH3O1-苯基-2-氨基丙烷(苯异丙胺)(安非他命)1-甲基-4-苯基哌啶-4-羧酸乙酯(度冷丁)而某些胺类化合物除有强的生理活性外,还可使人产生很强的依赖性,这些化合物已成为公认的毒品。NH3CHH..112.9o105.90o0.147nmNH3CCH3CH3..108o0.147nmN..113.9o胺和氨一样,氮原子为sp3杂化,三个sp3杂化轨道分别与氢或碳原子形成三个σ键,剩下一个sp3杂化轨道被一对电子占据。例如甲胺、三甲胺均为棱锥形结构,苯胺中的氮原子则接近平面构型.其杂化状态在sp3与sp2之间.3.2.1胺的命名CH3NH2(CH3)2NH(CH3CH2)3N甲胺二甲胺三乙胺NH2NH2CH3NHCH3N(CH3)2苯胺邻甲基苯胺N-甲基苯胺N,N-二甲基苯胺H3CCHNH2CHCHCH3CH3CH3CH3CH2CHCHCH3N(C2H5)2CH2CH32-氨基-3,4-二甲基戊烷3-(N,N-二乙氨基)-4-甲基己烷季铵盐的命名与铵盐相似。如:(CH3CH2CH2CH2)4N+Br-(CH3CH2)4N+Cl-溴化四丁基铵氯化四乙基铵3.2.2胺的化学性质(1)胺的碱性各类胺的碱性次序和影响因素。气相:NH3<C2H5NH2<(C2H5)2NH<(C2H5)3N溶液中:RNH2+H2ORNH3+OH[RNH3+][OH-][RNH2]Kb=NH3<C2H5NH2<(C2H5)3N<(C2H5)2NHpKa9.2510.8010.8511.09pKb4.763.363.253.06烷基供电子的诱导效应与水的溶剂化效应二者综合作用的结果,造成了胺在水中的碱性强度次序。R3N-HOHH:R2NHHOHHOHH::仲胺的溶剂化情况叔胺的溶剂化情况芳香胺的碱性比氨和脂肪胺弱,这是由于氮原子上孤对电子通过p-π共轭部分地向苯环转移,形成更稳定的共轭体系,使氮原子与质子的结合能力降低。:NH2在酰胺中,由于羰基的吸电子性,酰胺的碱性比胺弱。酰胺与酸不能形成铵盐。RCONH2(2)(3)CH3CH2NH2HO(CH2)2NH2HO(CH2)3NH2NH2NO2NH2ClNH2NO2NH2NO2(5)NH2NH2OC2H5NH2NO2NH2COOC2H5NO2(1)思考题:试比较下列各组化合物的碱性强弱NH2NH2ClNH2NO2NH2CH3H2CCHCH2NH2HCCCH2NH2CH3CH2CH2NH2(4)(2)烃化反应R-NH2+R1-XRNH2R1X-RNH2R1X-+RNH2RNHR1+RNH3X-RR1NH+R1-X+RNHR12X-RNHR12X+RNH2RNR12+RNH3X-R13NRX-RNR12+R1-X+季铵盐(3)酰化反应伯胺与仲胺与酰氯、酸酐和酯作用生成酰胺N:HRCOClNHCOClRNCOR-HCl++OCROCORN:HNHCOOCORRNCORRCO2H++OCROR'N:HNHCOOR'RNCORR'OH++CH3SO2NHRCH3SO2NRNa+NaOH+H2OSO2ClCH3CH3SO2NR2+R2NHSO2ClCH3CH3SO2NR3Cl+R3N+因此可以利用胺的磺酰化反应来鉴定或分离三种胺Hinsberg反应:SO2ClCH3CH3SO2NHR+RNH2(4)与亚硝酸反应Cl-OH--H+R-ClR-OH重排烯新的碳正离子R+RNH2+NaNO2+2HClRNNCl-++NaCl+2H2ORNNCl-+-N2R++Cl-ArNNClArNH2+NaNO2+2HCl++NaCl+2H2O0~5℃(C2H5)2NHNaNO2,HCl(C2H5)2N-N=ON-亚硝基二乙胺NHCH3NCH3NONaNO2,HCl(5)芳胺环上的亲电取代反应NH2NH2BrBrBr+Br2+HBrNH2NHCOCH3NHCOCH3NH2(CH3O)2OBr2CH3COOHBrBrH3ONH2NH.SO3HNH2.H2SO4NH2-H2O180℃SO3H+H2SO4NH2NHCOCH3NHCOCH3NHCOCH3(CH3CO)2ONO2NO2HNO3,乙酸中HNO3,乙酐中3.2.3胺的制法(1)氨和胺的直接烃化NaHCO3,H2O90~95℃NH3+R—XR—NH2+NH+4X-C6H5NH2+C6H5CH2ClC6H5NHCH2C6H5N-苄基苯胺RNH3+X-RNH3+X-+NH3(2)Gabriel合成法ON-K+ORXONORKXONOCOONaCOONaRH2ORNH2纯伯胺++++2NaOH(3)硝基化合物还原C6H5NO2C6H5NH21.Fe,HCl2.OH-NO2ClNH2Cl1.Fe,HCl2.OH-NO2NH2CHOCHOSnCl2+HClNO2NO2NO2NH2NaSH,EtOH或(NH4)2S,EtOH(4)腈、肟和酰胺的还原RCNRCHNOHRCH2NH2RCONH2RCH2NH2催化氢化或化学还原法RCONHR1RCONR1R2催化氢化或化学还原法RCH2NHR1RCH2NR1R2CNLiAlH4CH2NH2(5)酰胺降解反应(Hofmann重排)RCONH2Br2H2O++4NaOHRNH2+2NaBr+Na2CO3+H2O(CH3)3CCH2CONH2NaOBr(CH3)3CCH2NH2或Br2+NaOH,H2O新戊胺94%CH3(CH2)8CONH2Cl2,NaOHH2OCH3(CH2)7CH2NH23.3重氮和偶氮化合物含有-N=N-的结构,一端与碳原子相连,另一端与卤素原子、氧原子等相连为重氮化合物;两端都与碳原子相连,则为偶氮化合物。NNNNOH氯化重氮苯氰化重氮苯苯基重氮酸重氮甲烷偶氮苯对羟基偶氮苯CH3CH3CNCNNCCH3CNCH3NN(CH3)2NSO3H偶氮二异丁腈4-[4-(二甲氨基)苯基]偶氮苯磺酸NNCl-NNCNNN-OHCH2N2+(1)偶合反应NH2NNCl-+NaNO2+2HCl0~5℃++NaCl+2H2O3.3.1重氮盐的化学反应NNCl-NH2NNNH++苯基重氮氨基苯NNNHH+NNNH230~45℃NNNN+NN+N(CH3)2NNN(CH3)2-H+NNN(CH3)2H+..NNCl-OHNNOHOH-++0℃NH2HO3SNaNO2,HClNHO3SNCl-N2+Cl-HO3SN(CH3)2CH3COOHNHO3SNN(CH3)2NaOHNNaO3SNN(CH3)2++甲基橙N-O3SNN(CH3)2NHHO3SNH+OH-N(CH3)2+黄色红色(2)取代反应CH3NH2NaNO2,HClCH3N2+Cl-CuCl,HClCH3Cl+N20~5℃NH2ClNaNO2,HBrN2+Br-ClCuBr,HBrBrCl0~20℃+N2CH3NH2NaNO2,HClCH3N2+Cl-CuCNCH3CN+N20℃重氮盐在亚铜盐(CuCl.CuBr.CuCN)的催化下重氮基被氯、溴或氰基取代的反应称为Sandmeyer反应。CH3NH2NaNO2HBF4CH3N2+BF4-CH3F△NH2NaNO2,HClN2Cl-HBF4N2BF4-F++△NH2N2Cl-NaNO2,HClKII+N2+0~5℃25℃BrNH2NaNO2,H2SO4BrN2+HSO4H+,H2OBrOH△H3CNH2NaNO2,HClH3CN2+Cl-H3PO2H3C或C2H5OH,25℃0~5℃3.3.2芳香重氮盐在有机合成中的应用CH3NH2(CH3CO)2OCH3NHCOCH31.Br2CH3NH2BrNaNO2,HClCH3N2ClBrH3PO2,H2OCH3Br1.HNO3,H2SO4NH2Br2NH2BrBrBrNaNO2N2ClBrBrBrH3PO2BrBrBr2.OH-,H2O0~5℃0~5℃HCl,25℃2.Sn+HCl
本文标题:43含氮有机化合物
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