2,6-二氯-4-乙酰基苯基磷酸的合成

制备了酸性磷酸酶检测底物2，6-二氯-4-乙酰基苯基磷酸酯（DCAP-P）。以2，6-二氯苯酚为原料，经酰化反应、AlCl3催化F-C重排、碱化成盐、磷酯化、水解等5步反应，制备了DCAP-P，并对F-C重排、磷酯化条件进行了改进。     

Hydrogen bonds in 4-dihydroxymethylpyridinium 2,6-dichloro-4-nitrophenolate

The ionic adduct of 2,6-dichloro-4-nitrophenol with 4-formylpyridine (which transforms into 4-dihydroxymethylpyridine), crystallizes in the space group P2₁/c with a = 12.264(2), b = 6.730(1), c = 16.731(3) Å, β = 99.46(3)° and Z = 4. Relatively long N⁺---HO⁻ hydrogen bonds (R_N = 2.683(3) Å are formed with strongly asymmetric location of the H-atom. This is well reflected both in IR and UV-VIS spectra. One of the gem diol OH group is attached to the phenolate oxygen atom and the second is engaged in the formation of infinite polyanionic chains via O---HO hydrogen bonds between OH groups.     

2,6-二甲基-3,5-二氯-4-吡啶酚糖苷的合成

在相转移催化条件下, 使 a-D-乙酰基化溴代的葡萄糖、半乳糖、葡萄糖醛酸甲酯1a, 1b, 1c分别与2,6-二甲基-3,5-二氯-4-吡啶酚(俗称氯吡醇, 氯羟吡啶)作用, 合成了氯吡醇的糖苷: 1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4,6-四-O-乙酰基-β-D-葡萄吡喃糖苷(2a), 1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4,6-四-O-乙酰基β-D-半乳吡喃糖苷(2b), 1-O-(2'6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4-三-O-乙酰基-β-D-葡萄吡喃糖醛酸甲酯(2c)。2a, 2b, 2c分别在甲醇中氨解, 相应得到: 1-O-(2', 6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-葡萄吡喃糖苷(3a), 1-O(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-半乳吡喃糖苷(3b),1-O-(2', 6'-二甲基-3',5'-二氯-(4'-吡啶基)-β-D-葡萄吡喃糖醛酸酰胺(3c)。2c用CH~3ONa/CH~3OH处理, 得到1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-葡萄吡喃糖醛酸甲酯(3d)。     

Synthesis of novel 1-[(2,6-dichloro-4-trifluoromethyl)phenyl]-3-aryl-1H-pyrazole-4-carbaldehydes

A series of novel 1-[(2,6-dichloro-4-trifluoromethyl)phenyl]-3-aryl-1H-pyrazole-4-carbaldehydes were synthesized using the Vilsmeier-Haack reagent. The structures of all the title compounds have been confirmed by elemental analysis, 1H-NMR and 13C-NMR and in addition, the structure of intermediate 5b was investigated by X-ray crystallography.     

Regioselective synthesis of 1-(2,6-dichloro-4-trifluoromethylphenyl)- 4-alkyl-1H-[1,2,3]-triazoles

A new and efficient method for the synthesis of 1-(2,6-dichloro-4-trifluoromethylphenyl)-4-alkyl-1H-[1,2,3]-triazoles by the room temperature 1,3-dipolar cycloaddition of (2-azido-1,3-dichloro-5-trifluoromethyl)benzene with terminal alkynes in the presence of Cu (I) salt as catalyst is reported. All the reactions gave 1,4-disubstituted products with high regioselectivity, as no 1,5-disubstituted product was formed. The structures of all the title compounds have been confirmed by elemental analysis, 1H- and 13C-NMR and in addition, the structure of compound 5a was investigated by X-ray crystallography.     

Peculiarities in the Fischer cyclization of 2,6-dichloro-4-pyridylhydrazones

The peculiarities of the Fischer cyclization of 2,6-dichloro-4-pyridylhydrazones were examined. It is shown that the introduction of chlorine atoms into the , position of the pyridine ring in all cases reduces the deactivating effect of the electron-acceptor pyridine nitrogen in this reaction and the Arbuzov modification (catalytic method). During thermal indolization, the process is shifted to favor the primary formation of 2,6-dichloro-4-aminopyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1638–1641, December, 1972.     

Photolysis of 2,6 di-tert-butyl-4-tert-butylperoxy-4-methyl-2,5-cyclohexadienone

The photolysis of a heptane solution of 2,6-di-tert-butyl-4-tert-butylperoxy-4-methyl- 2,5-cyclohexadienone (1) with light of 360–480 nm in the presence of 2,6-di-tert-butyl-4-methylphenol or 2,4,6-tri-tert-butylphenol gives rise to their corresponding phenoxyls in a reaction with the tert-butoxyl arising in the photolysis. Direct evidence of the formation of t-BuO^. by the photolysis of 1 was provided by the ESR characterization of spin-adducts of this radical with nitrosobenzene and nitrosodurene. Evidence of the photolysis of the peroxide bond in 1 is important for the mechanism of reaction of phenolic chain-breaking antioxidants.     

NQR investigations of 35Cl in crystalline 2,5-dichloro-4-nitroaniline

Two NQR lines were observed for ³⁵Cl in 2,5-dichloro-4-nitroaniline at room temperature, using a self-quenched super-regenerative spectrometer. Analysis of the Zeeman effect on the two lines using a cylindrical single crystal reveals that the crystal belongs to the monoclinic system. The principal field gradient Z axes enclose an angle of 35° and 28° in the cases of the low and high frequency resonance lines, respectively. The b axis is parallel to 81°, 280°. The unit cell contains either two or a multiple of two molecules. The molecules in the crystal can be arranged into two sets, with the molecular planes in each set being parallel among each other. The angle subtended between the two planes is 159° and each of the planes is inclined to the b axis at an angle of 79.5°. There is an in-plane bending of the two C? Cl bonds by 5.5°. The ionic, single bond and double bond characters of the C? Cl bonds for both chlorines are almost equal, and are in the ratio 24:73:3.     

Unusual regioselective reaction of 2,6-dichloro-4-methylnicotinonitrile with malononitrile dimer

Russian Chemical Bulletin - The reaction of 2,6-dichloro-4-methylnicotinonitrile with malononitrile dimer in the presence of triethylamine leads to regioselective nucleophilic substitution of the...     

Simple and efficient access to pyrazine-2,5- and -2,6-dicarbaldehydes

Efficient two-step synthesis of pyrazine-2,5- and -2,6-dicarbaldehydes is presented that consists of transformation of easily available corresponding dimethylpyrazines to distyryl derivatives and oxidation of the latter with the tandem system of osmium tetroxide/periodate ions. The proper choice of dehydration agent in the first reaction step and the good efficiency of the subsequent low-temperature oxidation are the key points of the developed protocol. Other examined synthesis routes were much less successful, but one of them leads to new powerful routes to methyl (5-hydroxymethyl)pyrazine-2-carboxylate and dimethyl 3,4-dihydropyrazine-2,6-dicarboxylate. Previously unknown characteristics of the title compounds are reported.     

Experimental and computational thermochemical study of 2- and 3-thiopheneacetic acid methyl esters

Thiophene-based compounds have widespread use in modern drug design, biodiagnostics, electronic and optoelectronic devices, and conductive polymers. The present study reports an experimental and computational thermochemical study on the relative stabilities of 2- and 3-thiopheneacetic acid methyl esters. The enthalpies of combustion and vaporization were measured by a rotating-bomb combustion calorimeter, Calvet microcalorimetry, and correlation gas chromatography, and the gas-phase enthalpies of formation at T=298.15 K were determined. Standard ab initio molecular orbital calculations at the G3 level were performed, and a theoretical study of the molecular and electronic structure of the compounds studied was carried out. Calculated enthalpies of formation, using atomization and isodesmic reactions are in very good agreement with the experimental results.     

用DCNPNPT测定江水中季铵盐型阳离子表面活性剂

利用三氮烯类试剂与季铵盐型阳离子表面活性剂形成离子缔合物可用于季铵盐型阳离子表面活性剂的测定。如用HDNPAPT[1]、HDAA[2]测定CTMAB、CPB,但其灵敏度有待提高。本文研究了显色剂1 (2,6 二氯 4 硝基苯) 3 (4 硝基苯) 三氮烯(DCNPNPT)[3]与阳离子表面活性剂的显色反应,结果表明,DCNPNPT与CTMAB、CPB反应的表观摩尔吸光系数分别为3 93×104L·mol 1·cm 1,和4 16×104L·mol 1·cm 1,是目前报道的用光度法测定季铵盐型阳离子表面活性剂较灵敏的体系之一。用此法测定了瓯江水中微量阳离子表面活性剂CTMAB、CPB的…     

Synthesis and crystal structure of thermochroic 2,6-di-tert-butyl-4-dimethylamino-4-(2-hydroxyphenyl) cyclohexadien-2,5-one

The compound 2,6-di-tert-butyl-4-dimethylamino-4-(2-hydroxyphenyl)cyclohexadien-2,5-one is synthesized and its structure is studied. The thermochromism of the compound is due to cleavage on excitation of the C_spiro-N bond, which is lengthened to 1.512 Å under normal conditions, and O N proton transfer. A deeply colored diphenoquinone and dimethylamine are formed. The C_spiro-N bond is lengthened due to mutual steric repulsion of the atoms bound to C⁴ and N.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1808–1813, August, 1991.     

Reaction of 2,6-dibutylaminohepta-2,5-dien-4-one with malononitrile

Malononitrile reacted with the title compound to give 6-amino-5-cyano-2-(3,3-dicyano-2-methylallylidene-4-methyl-2H-pyran (3). Treatment of 3 with hot 80% sulfuric acid yielded 4,7-dimethyl-56-hydroxy-2(1H)quinolone. With concentrated aqueous sodium hydroxide, 3 gave 5-amino-3,6-dicyano-4,7-dimethyl-2(1H)quinolone and 5-amino-6-carbamoyl-3-cyano-4,7-dimethyl-2(1H)quinolone. The reaction of 3 with hydrochloric in acetic acid gave a mixture of 6-amino-3,7-dicyano-2,8-dimethyl-4-quinolizone and 3-cyano-4-methyl-6-(3,3-dicyano-2-methylallyl)-2-pyrone. Compound 3 also reacted with methylamine, butylamine and piperidine to give 8-amino-5-cyano-4-methyl-2-pyridone, 6-bulylamino-5-cyano-4-methyl-2-pyridone and 5-eyano-4-methyl-6-piperidino-2-pyridone respectively.