Synthesis and Crystal Structure of 6-(3''''-Indolyl)-8-(p-chlorophenyl)-10,10dimethyl-10H-pyrido [1,2-a] Indolium Perchlorate

1 INTRODUCTION The substituted 10H-pyrido [1,2-a] indolium per-chlorate can be used as photosensitive dyestuff andfluorescent whitener or organic light-guide sensiti-zers. Its properties have the relationship with the struc-ture, especially the conjugate…     

8-(4-取代苯基)-10,10-二甲基-6-苯基-10 H-吡啶并[1,2-a]吲哚盐的合成

2,3,3-三甲基-3H-吲哚高氯酸盐与取代查耳酮在异戊醇中反应,得到五种新的8-(4-取代苯基)-10,10-二甲基-6-苯基-10 H-吡啶并[1,2-a]吲哚盐[R=Me_2N-(3a),R=MeO-(3b);R=Br-(3c),R=H-(3d);R=O_2N-(3e)]通过元素分析和光谱测定确证了产物的结构。紫外光谱表明,λ_(max)与R有关,其次序为Me_2N—>MeO—>Br—>H—>O_2N—     

9,9-二甲基-2-(4-硝基苯基)-4-苯基-9H-吡啶并[1,2-a]吲哚高氯酸盐的微波合成及晶体结构

在微波辐射条件下,由2,3,3-三甲基-3H-吲哚高氯酸盐、1-苯基-3-(4'-硝基苯基)-2-丙烯-1-酮与哌啶合成了标题化合物.在甲醇/乙醇=1/1(V/V)中培养出单晶,通过X射线单晶结构分析法测定了分子结构和晶体结构,晶体属于单斜晶系,P2(1)/n空间群,其晶胞参数为:a=1.2507(4)nm,b=1.4378(4)nm,c=1.3033(4)nm,V=2.3366(12)nm3,Dc=1.401g/cm3,μ=0.210mm-1,F(000)=1024,Z=4,R1=0.0553,wR2=0.0732.     

6-(4-取代苯乙烯基)-8-(4-取代苯基)-10,10-二甲基-10H-吡啶并[1,2-a]吲哚盐的合成

通过2,3,3-三甲基-3H-吲哚高氯酸盐与取代双亚苄基丙酮在异戊醇中的反应,合成五种新的6-(4-取代苯乙烯基)-8-(4-取代苯基)-10,10-二甲基-10H-吡啶并[1,2-a]吲哚盐[R=H(3a),Cl(3b),Br(3c),MeO(3d),Me_2N(3e)]。     

取代10H-吡啶并[1,2-a]吲哚盐的^1H NMR与 结构的关系

本文对取代10H-吡啶并[1,2-a]吲哚盐的核磁共振氢谱进行了研究, 通过讨论6,8位取代基对吡啶环氢化学位移的影响发现8位取代基显著地改变了δ值,而6位取代基则对δ影响较小.     

Structure and reactivity of 2-methyl-9-hydroxy-4H-pyrido[1,2-a]pyrimidin-4-one

It has been shown that the alkylation of 2-methyl-9-hydroxy-4H-pyrido[1,2-a]pyrimidin-4-one takes place at the oxygen atom, but electrophilic substitution takes place mainly at position 8 of the molecule (the ortho position relative to the hydroxy group).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1660–1666, December, 1992.     

Electronic structure of 4H-pyrido[1,2-a]pyrimidin-4-ones

The characteristic features of ir and uv spectra of 43 4H-pyrido[1,2-a]pyrimidin-4-one derivatives with electron donor or acceptor groups in position 3, and positions 6, 7, 8, or 9, respectively, have been systematically studied. On the basis of the spectra some conclusions have been drawn for the molecular structure. The negative solvent effect of the lowest-energy π → π* transition is investigated by the PPP method.     

Syntheses of 10-Oxo-10H-pyrido[1,2-a]thieno[3,4-d]pyrimidines and 10-Oxo-10H-pyrido[1,2-a]thieno[3,2-d]pyrimidines from methyl tetrahydro-4-oxo-3-thiophenecarboxylate and methyl tetrahydro-3-oxo-2-thiophenecarboxylate,respectively

A general synthesis of 10-Oxo-10H-pyrido[1,2-a]thieno[3,4-d]pyrimidines and 10-Oxo-10H-pyrido[1,2-a]-thieno[3,2-d]pyrimidines is described. Methyl tetrahydro-4-oxo-3-thiophenecarboxylate ( 13 ) was condensed with 6-aminonicotinic acid ( 18 ) to give 3,10-dihydro-10-oxo-1H-pyrido[1,2-a]thieno[3,4-d]pyrimidine-7-carboxylic acid ( 19 ). Treatment of 19 successively with chlorotrimethylsilane, N-chlorosuccinimide and water gave 10-oxo-10H-pyrido[1,2-a]thieno[3,4-d]pyrimidine-7-carboxylic acid ( 17 ). Methyl tetrahydro-3-oxo-2-thiophenecarboxylate ( 21 ) was converted to 10-oxo-10H-pyrido[1,2-a]thieno[3,2-d]pyrimidine-7-carboxylic acid ( 25 ) by an analogous route.     

Acetylene-driven multi-molecular assemblies of high complexity: imidazo[1,2-a]pyridines and 5-chloro-N-[2-(imidazo[1,2-a]pyridin-6-yl)vinyl]pyridin-2-amine

Acetylene reacts with 2-aminopyridines in the superbase system KOBu^t/DMSO (the initial acetylene pressure ∼8 atm, 80 °C, 5 min) to give 2,3-dimethylimidazo[1,2-α]-pyridines in up to 60% yields. In the case of 2-amino-5-chloropyridine, along with ‘normal’ product, (Z)-5-chloro- N-[2-(2,3-dimethylimidazo[1,2-α]pyridin-6-yl)vinyl]pyridin-2-amine is formed in 40% yield. These multi-molecular assemblies involve parallel nucleophilic addition of N-centered anions to the triple bond and ethynylation of the forming C=N bond.     

Synthesis and molecular structure of 3,7-dimethyl-2-[N-(4-methylpyridyl-2)-4-hydroxy-3-methyl-5-oxopyrrolen-3-yl-2]imidazo[1,2-a]pyridine

Heterocyclization of 2-chloroepoxy-1,1-diethoxy-2.3-butane with 2-amino-4-methylpyridine occurred with participation of all three potential electrophilic centers to give 3,7-dimethyl-2-[N-(4-methylpyridyl-2)-4-hydroxy-3-methyl-5-oxopyrrolen-3-yl]imidazo[1,2-a]pyridine, the structure of which was determined by X-ray crystallography. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, 1089–1094, July 2006.     

Amino acids in the synthesis of heterocyclic systems. The synthesis of 4-oxo-4H-pyrido[1,2-a]pyridines and 4-oxo-4H-pyrido[1,2-a]pyrimidines

The pyridine and quinoline derivatives 2, 3 , and 6 with an activated methylene group atα-position in respect to the ring nitrogen atom were converted with 1, 8 , or 9 into fused pyrido[1,2-a]pyridine derivatives 4, 5, 7 , and 10 . In an analogous manner were the aminopyridines 16 and 17 transformed with thiazolone 9 into pyrido[1,2-a]pyrimidine derivatives 20, 21, 25 , and 26 .     

Novel routes to 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazines and 5,6,9,10,11,11a-hexahydro-8H-pyrido[1,2-a]pyrrolo[2,1-c]pyrazines

Condensation reactions of benzotriazole and 2-(pyrrol-1-yl)-1-ethylamine (1) with formaldehyde and glutaric dialdehyde, respectively, afforded intermediates 2 and 6. Subsequent nucleophilic substitutions of the benzotriazole group in 2 and 6 with Grignard reagents, sodium cyanide, and sodium borohydride gave 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazines 3a-e, 4, 5 and 5,6,9,10,11,11a-hexahydro-8H-pyrido[1,2-a]pyrrolo[2,1-c]pyrazines 7a-c, 8, 9, respectively, in good yields.