Microwave-induced by-products in the synthesis of 2-(4-methyl-2-phenylpiperazinyl)pyridine-3-carbonitrile

The Letter describes the investigation of an industrial reaction of N-methylphenylpiperazine and chloronicotinonitrile, under microwave heating. Besides the formation of the expected 2-(4-methyl-2-phenylpiperazinyl)pyridine-3-carbonitrile (4), extension of the scale leads to unexpected by-products. A specific pathway due to the formation of a reactive ‘ionic alkylating intermediate’ formed in situ under microwave conditions is proposed to explain the results observed.     

微波辐射下一锅法合成2-氨基-6-溴-4-芳基-5H-茚并[1,2-b]吡啶-3-腈衍生物

以芳香醛、4-溴茚酮、丙二腈和醋酸铵为原料,分别用微波辐射和传统加热法,一步法合成7种未见文献报道的2-氨基-6-溴基-4-芳基-5H-茚并[1,2-b]吡啶-3-腈衍生物.对比两种方法,在常压下微波具有反应时间短、产率较高等特点.所有化合物均经IR,1HNMR和元素分析确定.     

微波辐射快速合成2-(2＇-羟苯基)-5(6)取代苯并咪唑衍生物

苯并咪唑衍生物具有一定的抗病毒能力[1],一些苯并咪唑衍生物已用作农用抗植物病毒剂[2].一锅煮合成反应时间较长,产率中等[3,4].本文用取代邻苯二胺和水杨酸为原料,吡啶为溶剂,POCl3为催化剂,微波辐射法合成了标题化合物.     

Bromo derivatives of 1-(4-hydroxyphenyl)dihydrouracil and 1-(4-hydroxyphenyl)-5- or -6-metehyldihydrouracils

Bromination of 1-(4-hydroxyphenyl)dihydrouracil and its 6-methyl derivative with bromine in refluxing acetic acid gave 1-(3,5-dibromo-4-hydroxyphenyl)-5-bromo-, 1-(3,5-dibromo-4-hydroxyphenyl)-5-bromo-, and 1-(3,5-dibromo-4-hydroxyphenyl)-5-bromo-6-methyldihydrouracils and 1-(3,5-dibromo-4-hydroxyphenyl)-5-methyluracil. 5-Bromo- and 5,5-dibromodihydrouracils were dehydrobrominated, and the same compounds undergo decomposition to 3,5-dibromo-4-hydroxyphenylurea upon alkaline hydrolysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1251–1254, September, 1982.     

Synthesis of 4-Acyl-2-amino-6-(arylsulfanyl)pyridine-3,5-dicarbonitriles

Russian Journal of Organic Chemistry - The reaction of 4-acyl-2-amino-6-chloropyridine-3,5-dicarbonitriles with aromatic thiols in 1,4-dioxane in the presence of triethylamine led to the formation...     

1-(pyridine-2-carboxymethyl)silatrane

Russian Journal of General Chemistry -     

2-(2-hydroxyphenyl)-2-adamantanol in Ritter reaction

2-Substituted 4H-1,3-benzoxazines were obtained by the condensation of 2-(2-hydroxyphenyl)-2-adamantanol with aromatic and aliphatic nitriles in trifluoroacetic acid. With acetonitrile the classic product of Ritter reaction, a secondary amide, was isolated.     

Phenylarsenic(III) complexes of 2-(2-hydroxyphenyl)benzothiazolines

Equimolar reactions of PhAs(OMe)₂ (prepared in situ) and 2-(2-hydroxyphenyl)benzothiazolines LH₂ give the addition products PhAs(OMe)₂LH₂, while equimolar reactions of PhAsCl₂ with Na₂L yield substitution products PhAsL. All these derivatives have been characterized by elemental analyses and their plausible structures have been established on the basis of physico-chemical, IR, and NMR (¹H and ¹³C) spectral studies. © 2003 Wiley Periodicals, Inc. 15:92–96, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.10220     

Synthesis and Crystal Structure Analysis of 2-（3,5-Di-tert-butyl-2-hydroxyphenyl）-2-（3,4- dimethylphenyl） Acetic Acid Dimethylamine Salt

A new compound 2-（3,5-di-tert-butyl-2-hydroxyphenyl）-2-（3,4-dimethylphenyl） acetic acid dimethylamine salt （[NH2（CH3）2][C24H31O3]） was synthesized and structurally determined. It is of monoclinic system, space group P21/c with a = 14.731（2）, b = 10.1185（10）, c = 17.065（2） A^°, β = 98.293（10）° ,Z = 4, V = 2517.0（6）A^°^3, Dc = 1.091 g/cm^3, F（000） = 904 and Mr= 413.58. The dihedral angle defined by two benzene rings is 98.23°.     

Synthesis and Crystal Structure of （3R,4R）-5-（2,4-Dichlorobenzoyl）-4-（4-nitrophenyl）-6-（phenylamino）-3,4-dihydro-2H-thiopyran-3-carbonitrile

The title compound(C25H16Cl2N3O3S),as a thiopyran derivative,has been synthe-sized by the cyclization of an organic intermediate obtained from Baylis-Hillman adducts with a β-aroylthioamide using copper(I) salt as the catalyst.The crystal belongs to the monoclinic system,space group P21/c with a = 13.668(3),b = 8.4803(17) c = 21.999(4) ,β = 113.57(3)°,V = 2337.2(10) 3,Z = 4,Mr = 510.38,Dc = 1.451 g/cm3,μ = 0.401 mm-1,F(000) = 1048,the final R = 0.0487 and wR = 0.1079 for 3678 observed reflections with I > 2σ(I).     

Synthesis and Crystal Structure of (E)-2-(1-(2-Hydroxy-4-methoxyphenyl)ethylideneamino)-3-(4-hydroxyphenyl)methyl Propionate

(E)-2-(1-(2-Hydroxy-4-methoxyphenyl)ethylideneamino)-3-(4-hydroxyphenyl)methyl propionate (C22H27O6N, Mr = 401.45) has been synthesized by a condensation reaction of paeonol with tyrosin methyl ester hydrochloride, and its structure was determined by IR, NMR, HR MS and X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P21/c, with a = 11.91291(15), b = 9.49947(12), c = 19.8727(3) , β = 106.1104(15)°, V = 2160.60(5)3, Z = 4, Dc = 1.234 g/cm3, μ = 0.739 mm-1, F(000) = 856, R = 0.0466 and wR = 0.1461 for 3859 observed reflections with (Ⅰ> 2σ(Ⅰ)). In the crystal structure, the title compound is constructed by a centrosymmetric dimmer unit composed of a pair of π-π stacking enantiomers, and such units are linked by intermolecular O(5)-H(5)…O(1) and intramolecular N(1)-H(1)…O(1) hydrogen bonds.     

Efficient Synthesis of Methyl 6-(6-Aryl-1,2,4-triazin3-yl)pyridine-2-carboxylates

Russian Journal of Organic Chemistry - Methyl 6-(6-aryl-1,2,4-triazin-3-yl)pyridine-2-carboxylates were synthesized in up to 70% yield by one-step condensation of substituted...     

Rotamerisation and intramolecular proton transfer of 2-(2′-hydroxyphenyl)oxazole, 2-(2′-hydroxyphenyl)imidazole and 2-(2′-hydroxyphenyl)thiazole: a theoretical study

Semi-empirical (AM1-SCI) calculations have been performed on 2-(2′-hydroxyphenyl)oxazole (HPO), 2-(2′-hydroxyphenyl)imidazole (HPI) and 2-(2′-hydroxyphenyl)thiazole (HPT) to rationalise the photophysical behaviour of the compounds exhibiting intramolecular rotation as well as excited state intramolecular proton transfer (ESIPT). The calculations reveal that there is a gradual variation in the properties from HPO to HPT through HPI so far as the existence of the rotational isomers in the ground state is concerned. While HPO gives rise to two stable rotamers (I and II) in all the common solvents, there is only one stable species for HPT in the S₀ state. For HPI, rotamer II is possible only in the isolated state and/or in solvents of low polarity, but in high polar solvents it gives rise to the normal form (I) only. For all the molecules in the series, however, intramolecular proton transfer (IPT) takes place in the lowest excited singlet (S₁) and the triplet (T₁) states. Combination of the rotamerism and ESIPT gives rise to multiple fluorescence bands for the fluorophores. Theoretical assignments have been made for the excitation, fluorescence and phosphorescence bands. Simulated potential energy curves (PEC) in different electronic states reveal that the IPT process is feasible in either of the S₁ and T₁ states but not in the ground state. The ESIPT reaction has been found to be favoured both thermodynamically and kinetically in these electronic states compared to the ground state. However, quantum mechanical tunnelling has been proposed for the prototropic reaction to proceed in the excited states.