吡啶类化合物是目前杂环化合物中应用范围最广的品种之一,作为一种重要的精细化工原料,其衍生物主要包括烷基吡啶、卤代吡啶(如溴吡啶、氯吡啶)、氨基吡啶、甲基吡啶、碘吡啶、羟基吡啶、苄基吡啶、乙基吡啶、氰基吡啶、氟吡啶以及二氢吡啶等。其中,农药占吡啶系列产品消费总量的约50%,饲料添加剂约为30%,而医药及其他领域则约占20%。
吡啶是一种具有弱碱性和特殊气味的无色或微黄色液体,天然存在于煤焦油、页岩油、煤气及石油中。它能与水、醇、醚、石油醚、油类、苯、氯仿等多数有机溶剂混溶,是重要的化工原料和溶剂。
吡啶的重要衍生物包括烟酸、烟酰胺、异烟酰肼、烟碱、马钱子碱以及维生素B6等。吡啶具有接近正六角形的结构,与苯相似,拥有相同的电子结构。由于环中氮原子的吸电子作用,2,4,6位上的电子云密度低于3,5位,在酸性介质中,亲电取代反应主要发生在3,5位;而亲核反应如胺化、烷基化、芳基化和酰化则倾向于在2,4,6位进行。吡啶是一种弱的叔胺,在乙醇溶液中能与多种酸(如苦味酸、高氯酸等)形成不溶于水的盐;由于其呈碱性,还能与盐酸生成吡啶盐酸盐(C5H5N·HCl)。
在镍催化剂的作用下,通过200℃及15~30MPa的压力进行加氢还原可生成哌啶;也可电解还原为哌啶。吡啶的还原性比苯更容易。相比之下,吡啶较难氧化,但过氧化氢或过氧酸可以将其氧化成N-氧化吡啶,这是一个重要的吡啶衍生物。氮原子氧化后,吡啶不能形成带正电荷的吡啶离子,有利于芳基的亲电取代反应。吡啶的亲电取代如硝化、磺化和卤化都较为困难;但在200℃以上,可以通过卤化生成3,5-二氯吡啶或3,4,5-三氯吡啶。此外,吡啶能与多种金属离子形成结晶性的配位化合物。
中文名称 | 英文名称 | CAS号 | 化学式 | 结构式图片 |
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—— | 6,7-dihydro-3-methyl-6-oxo-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile | 52217-38-6 | C14H10N4O |
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—— | 2-picoline N-oxide | 931-19-1 | C6H7NO |
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—— | 3,5-Dinitropyridin-2-olate | 222548-10-9 | C5H2N3O5- |
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—— | 2,8-dibromo-[1,2,4]triazolo[1,5-a]pyridine | 1257705-07-9 | C6H3Br2N3 |
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—— | 1-(3-methyl-2-pyridinyl)piperazine dihydrochloride | 111960-11-3 | C10H15N3*ClH |
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—— | 5-bromopyrazolo[1,5-a]pyridine-3-carbaldehyde | 1101120-53-9 | C8H5BrN2O |
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—— | 1-(Pyridin-4-yl)cyclopropanamine dihydrochloride | 1228880-35-0 | C8H12Cl2N2 |
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—— | 6-bromo-2-fluoro-3-iodopyridine | 1599474-54-0 | C5H2BrFIN |
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—— | 1-(Piperazin-1-yl)phthalazine dihydrochloride | 1333898-02-4 | C12H16Cl2N4 |
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—— | 5,15-diphenyl-10,20-di(4-pyridyl)porphyrin | 71410-72-5 | C42H28N6 |
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—— | 3-(1-Hydroxyethyl)pyridine | 4754-27-2 | C7H8NO*H |
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—— | 5-isopropyl-3-methylpicolinonitrile | 1448776-85-9 | C10H12N2 |
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—— | bromozinc(1+),4-methyl-2H-pyridin-2-ide | 308795-93-9 | C6H6BrNZn |
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—— | zinc,3-methyl-2H-pyridin-2-ide,bromide | 308795-91-7 | C6H6BrNZn |
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—— | N-[(3-bromophenyl)methyl]-N-methylpyridin-3-amine | 436096-90-1 | C13H13BrN2 |
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—— | dimethyl 5,9-dihydroxy-7H-cyclohepta[b]pyridine-6,8-dicarboxylate | 39713-36-5 | C14H13NO6 |
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—— | tert-butyl (6-(chlorosulfonyl)pyridin-2-yl)carbamate | 2200293-12-3 | C10H13ClN2O4S |
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—— | 7-bromo-4-(5-(5-hexylthiophen-2-yl)thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-c]pyridine | 1334680-01-1 | C19H18BrN3S3 |
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—— | (2-Benzylpyridin-3-yl)(tert-butoxycarbonyl)carbamate | 1260810-99-8 | C18H19N2O4- |
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—— | 4-({4-[2-(5-Ethylpyridin-2-yl)ethoxy]phenyl}methyl)-1lambda~4~,3-thiazolidine-1,5-dione | 105390-47-4 | C19H22N2O3S |
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—— | (N-{phenyl[2-(pyridine-2-carboxamido)phenyl]methylidene}glycinato-N,N',N'',O)nickel(II) | 124302-98-3 | C21H15N3NiO3 |
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—— | 5-iodo-4-methyl-7H-pyrrolo[2,3-d]pyrimidine | 1303426-83-6 | C7H6IN3 |
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—— | 4-chloro-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine | 1354454-95-7 | C7H7ClN2 |
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—— | bis(2-phenylpyridinato)(2,2'-bipyridine)iridium(III) hexafluorophosphate | 106294-60-4 | C32H24IrN4*F6P |
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—— | Tris[4,4'-bis(t-butyl)-2,2'-bipyridine]ruthenium(II) hexafluorophosphate | 75777-87-6 | C54H72N6Ru+2 |
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—— | bromozinc(1+),6-methoxy-2H-pyridin-2-ide | 352530-39-3 | C6H6BrNOZn |
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—— | 2,4,7-trichloro[2,3-d]pyrimidine-6-carbonitrile | 117506-01-1 | C8HCl3N4 |
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—— | borane, 5-ethyl-2-methyl-pyridine | 1006873-58-0 | BH3*C8H11N |
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—— | 18820-82-1 | BrH*C5H5N*As2O3 |
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—— | Bis(6-amino-2-pyridinaminium) sulfate | 146997-97-9 | C10H16N6O4S |
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—— | 5-Methoxy-2-methylpyrazolo[1,5-a]pyridine-3-carboxylic acid ethyl ester | 1352393-99-7 | C12H14N2O3 |
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—— | 2-chloro-4-iodo-5-(trifluoromethoxy)pyridine | 1221171-84-1 | C6H2ClF3INO |
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—— | 1,3-Bis-<3-(4-fluor-phenyl)-3-oxo-prop-1-enyl>-benzol | 7059-61-2 | C24H16F2O2 |
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—— | [(2-phenylpyridine)<sub>2</sub>Ir(μ-Cl)]<sub>2</sub> | 1413974-24-9 | C44H34Cl2Ir2N4 |
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—— | sodium 2-mercaptopyridine N-oxide hydrate | 304675-78-3 | C5H4NOS*H2O*Na |
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—— | 100-69-6 | C7H6N*H |
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—— | 945491-51-0 | C21H24ClIrN |
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—— | 6-bromo-3-iodo-2-methoxypyridine | 1310949-37-1 | C6H5BrINO |
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—— | tert-Butyl-N-(3-pyridyl)glycinate | 710939-70-1 | C11H16N2O2 |
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—— | 1-ethylpyridinium bis(trifluoromethylsulfonyl)imide | 712354-97-7 | C2F6NO4S2*C7H10N |
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—— | [1,2,4]triazolo[1,5-a]pyridine-7-carbaldehyde | 1268521-09-0 | C7H5N3O |
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—— | 2-(2'-pyridyl)-4-chloroquinoline | 954225-55-9 | C14H9ClN2 |
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—— | 3-Chloro-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-one | 1256806-34-4 | C7H5ClN2O |
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—— | 2,4,6-Triformyl-pyridin | 6390-09-6 | C8H5NO3 |
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—— | 6-Methoxy-N2-methylpyridine-2,3-diamine hydrochloride | 83732-72-3 | C7H12ClN3O |
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—— | 3,5-diamino-2,6-dimethoxypyridine dihydrochloride | 56216-28-5 | C7H11N3O2*2ClH |
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—— | 2-cyano-3-(pyridin-3-yl)acrylic acid | 103029-74-9 | C9H6N2O2 |
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—— | 3-Pyridinecarbonitrile, 1-butyl-1,2-dihydro-6-hydroxy-4-methyl-2-oxo- | 39108-47-9 | C11H14N2O2 |
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—— | Pyronaridine Tetraphosphate | 76748-86-2 | C29H44ClN5O18P4 |
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—— | 1-ethyl-5-cyano-6-hydroxy-4-methyl-2(1H)-pyridinone | 28141-13-1 | C9H10N2O2 |
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