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第二章烃化反应按被烃化物的结构分,烃化反应可分为:氧烃化氮烃化、碳烃化引入烃基的方式:取代、对双键加成在有机化合物分子中的C、N、O等原子上引入烃基的反应1.卤代烃为烃化剂Williamson合成:碱性下醇与卤代烃反应得混合醚R'X+ORR'OR+X一、醇的O-烃化第一节氧原子上的烃化反应ROH+BRO+HB①反应机理a.双分子亲核取代反应机理RO+R'H2CXCR'ROXHHROCH2R'+X反应速度:V=K[RO][R'CH2X]R-XRX慢+决定反应速率R+R'OHR-O-R'快R-O-R'+HH消旋产物Ph-CH2XR-CH=CH-CH2X叔卤代烷、、按SN1历程b.单分子机理反应速率:V=k[RX]①主要影响因素a.烃化剂的结构RIRBrRClRFRIRBrRCl当R相同C-X极化度活性:成本:i)活性(∵卤素的电负性)当X相同时ii)卤代丙烯,卤苄卤代烷卤芳烃ArXClNO2OEtNO2+EtOHNaOH非那西丁中间体当卤代烃为叔卤代烃时,不能在强碱下反应,易消除HX,可在中性或弱碱性下反应。CCH3CH3CH3+CH3-CCH2CH3Bb.碱和溶剂醇钠、Na、NaH、NaOH、KOH有机碱:六甲基磷酰胺(HMPA)、N,N-二甲基苯胺(DMA)、非质子溶剂:苯、甲苯(Tol)、二甲苯(xylene)、DMF、DMSO无水条件下质子性溶剂:ROX有助于R-CH2X解离,但是RO-易发生溶剂化,因此通常不用质子性溶剂c.醇的结构CH3ONa+ClCH2COOMeCH3OCH2COOMeCH3OH/pH=864℃R-OHEtOTlC6H6ROTlR'XCH3CNR-O-R'活性低的醇,可先制成其钠盐,再反应改进得Williamson醚合成法:将醇制成醇铊,再进行烃化另:卤代醇分子内的Williamson反应HOX碱OXO+X如:2CH3-CH=CH22HClCH3-CH-CH2ClCH3-CH-CH2OH+OHClCa(OH)22H3C-CH-CH2+CaCl22H2O+O2.芳磺酸酯为烃化剂例如,鲨肝醇的合成CH2OC18H37CHOHCH2OHCH2OHCHOHCH2OHCH2OHCHOCH2OCH3CH3Me2CO/HClC18H37OTs/KOH/Tol110℃,3hCH2OC18H37CHOCH2OCH3CH3EtOH/HCl,2h制备方法:ArSO2Cl+ROHNaOHArSO2OR+HCl3.环氧乙烷为烃化剂①羟乙基化反应例如:OCH2-CH2+C2H5OH-C2H5OCH2CH2OH当环氧乙烷过量时,易发生聚合反应。例如:OCH2OCOC17H33OHHOHOOHm(OH2CH2C)OO(CH2CH2O)nHO(CH2CH2O)pHCH2OCOC17H33OKOHH2O②、环氧乙烷的衍生物为烃化剂反应机理:a.在酸催化下CHHCRHOCHHCRHHObNuCRHCH2-OH+H+CHHCRHHONaaabRCH-CH2OH+◆R为推电子基,在a处断裂生成伯醇产物◆R为吸电子基,地b处断裂生成仲醇产物b.碱催化(双分子亲核取代反应)CH2CHORR'OCHCHOROR'RCHCH2OR'OR'OHRCHCH2OR'OH+R'O◆SN2双分子亲核取代,立体位阻原因为主,开环单一,反应发生在取代较少的碳原子上例如:(酸碱催化的比较)CH2CHOPh+MeOHH2SO4,5hMeONa,6hPhCHCH2OH+PhOMe(90%)CHCH2OMeOH(10%)PhCHCH2OH+PhOMe(25%)CHCH2OMeOH(75%)二、酚的O-烃化1.烃化剂OHR'+RXOHORR'+X+H2O①卤代烃*镇痛药邻乙氧基苯甲酰胺的合成*酚羟基的苄基化CONH2OHEtBr/NaOH80~100℃,190,000PaCONH2OEt(75%)HOOHBrPhCH2Cl/Me2CO/KI/K2CO3PhCH2OOCH2PhBr*中枢兴奋药甲氯酚酯中间体的合成*消炎镇痛药苄达明的合成NNCH2C6H5ONaNNCH2C6H5Cl(CH2)3N(CH3)2125-128℃,7hO(CH2)3N(CH3)2ClOHClClCH2COOH,NaOHPh8-9HClOCH2COOH②硫酸二甲酯CH3OHOCHOMe2SO4/NaOHCH3OCH3OCHO例如:HO(CH3)2SO4,NaOH75-80℃,1hH3CO抗高血压药甲基多巴的中间体消炎镇痛药萘普生的中间体③重氮甲烷2)选择性OMeOMeCOOMe过量CH2N2OHOHCOOH2molCH2N2OMeOHCOOMeNN+HORCH2NNCH3ORN2CH3OR(R=ArorR'CO-)1)反应机理④ROH/DCCb.应用NHCNHO+ArORPhOH+PhCH2OHDCC100℃PhOCH2Ph(96%)NCNHHORNCNHORHHOAra.反应机理⑤烷氧磷盐(R3P+OR’X-)EtOOC-N=N-COOEtPh3PPh3PNCOOEtN-COOEtROHHXEtOOCNHNHCOOEt+Ph3PORXPh3PORX+ArOHArOR+Ph3PO+HX另外,常用异丁烯、氯甲醚保护酚羟基,如:ArOH+CH3C=CH2CH3HArOC(CH3)3ArONaClCH2OCH3/TolArOCH2OCH32.位阻及螯合对烃化的影响①形成氢键的酚羟基的烃化较困难OHCOHOMeI/NaOHOHCOMeOOOHOHOOMeMeI/NaOHOOHOMeOOMe②解决方法OOOHOOOMeTsOH/MeOH180℃,20min.(100%)a.用氢化钠或烷基锂将酚变为盐类然后烃化b.在剧烈的条件下烃化3.多元酚的选择性烃化如:OHOH(CH3)2SO440℃20%NaOH(过量)20%NaOH(Ph8-9)C6H5NO2OCH3OCH3OHOCH3(83%)(90%)注:酚烃化时,除得到O-烃化产物外,有时还会得到C-烃化产物。如,OHOHHOOOO①CH3ONa②CH3IOHOHHOCH3CH3H3C①CH3I,CH3OH②CH3ONa,CH3OH,△OCH3OCH3H3CO三、醇、酚羟基保护第二节氮原子上的烃化反应一、氨及脂肪胺的N-烃化卤代烃与氨的烃化反应(氨基化反应)RX+NH3H3NCXRNH3XRNH2+NH4XNH3RX+RNH2R2NH2XR2NH+NH4XNH3RX+R2NHR3NHXR3N+NH4XNH3RX+R3NR4NX反应条件对氨化产物的影响1)投料比:氨过量,伯胺比例高。2)反应溶剂:常采用水和乙醇。3)催化剂:铵盐(NH4Cl,NH4NO3或胺的盐酸盐)NH4+NH3+H+例如:NO2NO2NO2NO2Cl+NH3AcONH4170℃,6hNH24)卤代烃的结构对氨化产物的影响立体位阻较小的卤代烃,氨化易形成叔胺;仲卤代烃及β位带有侧链的伯卤代烃与氨反应,产物中叔胺甚少。CHICH3CH3+NH3EtOH100℃,4.5hCHNHCH3CH32CHCH2CH3CH3+NH3EtOH110℃,3hCHCH2NH2CH3CH3Cl如:1.伯胺的制备①大过量的氨与卤代烃反应CH3CHCOOHBrNH3(70当量)CH3CHCOOHNH2(70%)②Gabriel反应NHOOKOH/EtOHNOOKRX/DMFNROONROONH2NH2HCl/H2ONHNHOO+RNH2OHOHOO+RNH2水合肼的水解机理NROONH2NH2NROHONHNH2RHNOONHNH2NHNHOOHRHNNHNOH2ONHROH2HNHNHOOHRH2NNHNHOHORNH2+例如,抗疟药伯胺喹的合成H2N(CH2)3CHCH3NCH3ONHNHOOBr(CH2)3CHCH3Br+Na2CO3145~150℃,2h(73%)NOO(CH2)3CHCH3Br6-甲氧基-8-氨基喹啉/Na2CO3140~145℃,8h(93%)NOO(CH2)3CHCH3NCH3ONHNH2NH2H2O/Alc,6h,(80%)NH(CH2)3CHCH3NCH3ONHNHNNaOH/Tol(30%)③改良的Gabriel反应(CF3SO2)2O+PhCH2NH2CH2Cl2NaOHn-C7H15PhCH2NSO2CF3C7H15-nNaH/DMF100℃3hPhCH=N-C7H15-n10%HCl/THF△3hTEA三乙胺n-C7H15NH2PhCH2NHSO2CF3④Délépine(德莱潘)反应活性卤代烃与环六亚甲基四胺的反应NNNNRXNNNNRXHClEtOHRNH2氯霉素中间体的合成书上72页⑤利用二苯硫基胺制备伯胺(PhS)2NHBuLi/THF20℃(PhS)2NLiRXRN(PhS)2HClRNH2⑥还原烃化反应1)反应分为加成与还原两步,且无季铵盐生成。NH3RCHORCHNH2OHH2H2RCH2NH2RCH2NH2RCH=NHH2RCH=NH+RCH2NH2RCHNHCH2RNH2(RCH2)2NH+NH3RCHO(RCH2)2NH(RCH2)2NCHROHH2(RCH2)3NRCH=NH+(RCH2)2NH(RCH2)2NCHRNH2H2(RCH2)3N+NH3例如:N-CH3N-CH3NCH3C6H5HONHCH3C6H5HOHCHO,H2,NiCH3ON-CH3NCH3OH2N2HCHO,H2,Ni(CH3)2N镇痛药阿法罗宁的中间体消炎镇痛药氨基比林2)还原剂:催化氢化、金属钠或钠汞齐-乙醇;锌粉;复氢化合物及甲酸等。3)醛、酮结构对产物的影响四碳以下的脂肪醛与氨在RaneyNi催化下还原烃化,产物为混合物。NH3n-PrCHO/H2/RaneyNin-BuNH2+n-Bu2NH+NEtEtPr-n(32%)(23%)(32%)五碳以上的脂肪醛与过量氨在镍催化下还原烃化主要得伯胺。苯甲醛与等摩尔氨还原烃化主要得苄胺。NH3PhCHO/H2/RaneyNi/AlcPhCH2NH2+(PhCH2)2NH(90%)(7%)脂肪酮与氨的还原烃化收率高低与酮的立体位阻有关芳香烷基酮及二芳基酮用上述法,收率较低。NH3+COMen-PrH2/RaneyNiCHNH2Men-Pr(90%)NH3+COMei-BuH2/RaneyNiCHNH2Mei-Bu(65%)NH3+COi-Pri-PrH2/RaneyNiCHNH2i-Pri-Pr(48%)2.仲胺的制备①仲卤代烃及β位带有侧链的伯卤代烃与氨或伯胺反应CHCH3CH3NH3(1.5mol)/AlcICHCH3CH32NHCHCH3CH3BrCH3NH2/Alc110℃,18hCHCH3CH3NHCH3+CHCH3CH32NCH3(78%)(少)②N-苄基三氯甲磺酰胺法RNH2(CF3SO2)2ORNHSO2CF3R'X/NaOHRNSO2CF3R'LiAlH4RR'NH③杂环卤代烃与胺类的反应1)氯喹的合成2)阿的平的合成NClCl苯酚135~138℃12hNClONClNHCH(CH2)3NEt2CH3NH2CH(CH2)3NEt2CH3NH2CH(CH2)3NEt2CH3ClOMe+PhOH110℃,4hNHOMe(91%)CH(CH2)3NEt2CH3④亚磷酸二酯与伯胺反应RNH2(EtO)2POHRNHP(OEt)2R'X/NaOHHClRR'NHCCl4ORR'NP(OEt)2O⑤Hinsberg反应⑥ROP+Ph3与伯胺反应RNH2ArSO2ClRNHSO2ArR'X/NaOH/H2ORR'NHNaOHRR'NSO2Ar酸或碱RNH2+R'OP+Ph3DMF或苯RR'NH+Ph2P=O⑦还原烃化反应1)脂肪醛酮与氨进行还原烃化,得混合物,仲胺收率低2)芳香醛与氨的克分子为2:1,还原烃化主要得仲胺RNH2+2PhCHO(PhCH2)2NH+PhCH2NH2H2/RaneyNi(81%)(12%)3.叔胺的合成①仲胺与卤代烃反应可得叔胺
本文标题:绿化养护合同
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