3-氰基吡啶与Grignard试剂的反应研究

3-取代酰基吡啶可由3-氰基吡啶与相应的卤代烷基镁加成,然后酸化水解来制备.我们曾用该法顺利地制备了一系列的3-取代酰基吡啶,另外还得到少量的4-烷基-3-取代酰基吡啶.但当用氯化苄基镁时,只得到少量的3-取代酰基吡啶,而主要产物却是4-苄基-3-氰基吡啶.为了探讨这两种反应中各组分的相对含量,用高压液相色谱分别对3-氰基吡啶与溴化丁基镁、氯化苄基镁的反应产物进行了分析.为了解释反应产物的异常现象,对反应物进行了量子化学计算,用前线轨道理论对以上反应进行了讨论.     

Vibrational analysis of halogenated derivatives of cyclobuten-3,4-ione-II. 1-Chloro-2-iodo-, 1-bromo-2-iodo- and 1,2-diiodocyclobuten-3,4-dione

The FTIR spectrum has been measured for the new compounds 1-chloro-2-iodo-, 1-bromo-2-iodo- and 1,2-diiodocyclobuten-3,4-dione in solution and as iso-oriented polycrystalline films in polarized radiation. Utilizing the corresponding vibrational assignment, and the results of a previous investigation, we propose a planar force field for all six 1,2-dihalogenocyclobuten-3,4-diones not containing fluorine.     

Preparation of 3-bromo-2-methylfuran and 4-bromo-2-methylfuran

4-endo-5-exo-Dibromo-3-methyl-3,6-endo-oxyperhydrophthalic anhydride 3b and 4-exo-5-endo-dibro-mo-3-methyl-3,6-endo-oxyperhydrophtbalic anhydride 3c were isolated from the bromo-adducts of 3-methyl-3,6-endo-oxy-1,2,3,6-tetrahydrophthalic anhydride 2. When 3b or 3c was heated in quinoline, only 3-bromo-2-methylfuran 4 was obtained from 3b and only 4-bromo-2-methylfuran 5 from 3c.     

Novel fragmentation reaction of 2-alkyl- and 2,4-dialkyl-3-iodo-1-oxocyclohexan-2,4-carbolactones

2-Alkyl- and 2,4-dialkyl-3-iodo-1-oxocyclohexan-2,4-carbolactones undergo lithium hydroxide- and lithium alkoxide-induced fragmentation reactions to provide butenolides, gamma-hydroxycyclohexenones, and/or gamma-butyrolactones. In general, product distribution is governed by two factors: (1) the nature of nucleophiles and (2) the steric bulkiness of the substituents at C-2 and C-4 of the cyclohexanones. Lithium hydroxide-induced fragmentation provides butenolides and gamma-hydroxycyclohexenones. In contrast, lithium alkoxide-promoted fragmentation results in predominantly 5-substituted gamma-butyrolactones along with a small amount of butenolides in limited cases. Fragmentation products induced by lithium hydroxide are largely influenced by the steric bulkiness of the substituents at C-2 and C-4 of the cyclohexanone ring. The bulky substituents render the exclusive formation of butenolides.     

双环戊二烯基二氯化钛催化下格氏试剂与偕二卤代烷的反应

本文作者进行了在双环戊二烯基二氯化钛催化下, 异丙基格氏试剂对偕二卤代烷的还原反应的研究, 这对扩大该催化还原体系的应用范围是有意义的。本文报道该反应的研究结果及可能的反应机理。     

2-Nitro-and 2-bromo-2-nitroethylphosphonates in the reaction with sodium azide

The reactions of phosphorylated 2-nitro-and 2-bromo-2-nitroethenes with sodium azide involve 1,3-dipolar cycloaddition to form triazoles, aziridines and isomeric vinyl azides. The latter products were isolated as a mixture of structural isomers. The structure of the obtained compounds was determined by IR and ¹H and ³¹P NMR spectroscopy.     

Formation of derivatives of thiazoline by the reaction of thiourea with 2-bromo-3-aminopropionic acid

Depending on the conditions employed, thiourea reacts with the hydrobromide of 2-bromo-3-aminopropionic acid to give a dihydrobromide or an internal salt S-(2-amino-1-carboxyethyl)isothiourea. This compound can also lose ammonia to give a thiazoline derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1687–1689, December, 1986.     

Self-condensation reaction of alkylbenzothiazoles with grignard reagents

2-alkylbenzothiazoles undergo Claisen-type self-condensation reaction simply on treatment with Grignard reagents.     

Formation of thienothiophenes in the high temperature reaction of 2-chlorothiophene with compounds containing the c2h5s group

The high temperature gas-phase reaction of 2-chlorothiophene with a mixture of diethyl disulfide and diethyl trisulfide constitutes a simple one-step synthesis of a 41 mixture of thieno[2,3-b]- and thieno[3,2-b]-thiophenes. Their total yield depends on the nature of the donor of the ethylthio group.Communication 30 of the series High temperature organic synthesis. For Communication 29, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1041–1044, August, 1988.     

Spectroelectrochemistry of intrinsically conducting furan-3-chlorothiophene copolymers

Electrochemical copolymerization of furan and 3-chlorothiophene was performed at constant electrode potential in a binary solvent system consisting of boron trifluoride diethyl etherate + ethyl ether (BFEE + EE; ratio 1:2) and trifluoroacetic acid (10% by volume). The homopolymers and copolymers obtained were studied with cyclic voltammetry, in situ ultraviolet–visible spectroscopy, in situ resonance Raman spectroscopy, and in situ conductivity measurements. The spectroelectrochemical properties of the copolymers show intermediate features between polyfuran and poly(3-chlorothiophene). The conductivity changes of homo- and copolymer films are almost completely reversible when the potential shift direction is reversed.

Vibrational analysis of alkyl iodides: 1-iodo-2- methylpropane and 1-iodo-3-methylbutane

Liquid and solid-state infrared spectra were obtained for 1-iodo-2-methylpropane and 1-iodo-3-methylbutane. The C-I stretching bands of the P_C and P_H' conformers of the propane were observed at 601 and 582 cm^?1, respectively, and those of the P_C and P_H conformers of the butane were observed at 595 and 512 cm^?1. Both conformers of each compound are present in the amorphous solid. Only the more sterically hindered P_H' conformer is present in the crystalline solid of the propane, and only the P_H conformer is present in the crystals of the butane. Vibrational assignments were made for both conformers of each compound with the aid of normal coordinate calculations. The increase in C-I stretching frequency of the P_H' conformer of the propane from the normal value in alkyi iodides (from ca. 500 to 582 cm^?1) is attributed to the increased contribution of C-C stretch and decreased contribution of C-I stretch.     

2-甲氧基-3-氟-4-碘吡啶的合成

2-甲氧基-3-氟-4-碘吡啶是一个重要的医药化工中间体,其合成路线未见文献报道。以2-甲氧基-3-氟-5-氯吡啶为起始原料,经氢解和碘代两步反应合成标题化合物,总收率62.8%,其结构经¹H NMR, ¹³C NMR和MS确证。     

On the reaction of 3-bromo-2-nitrobenzo[b]thiophene with some ortho-substituted anilines: an analysis of the products of reaction and of their NMR and MS properties

The title reaction, carried out in DMF in the presence of triethylamine or potassium carbonate, has furnished the ‘expected’ 3-amino-2-nitrobenzo[b]thiophenes 2o together with the ‘unexpected’ 2-amino-3-nitrobenzo[b]thiophenes 3o, thus recalling the situation observed with other weak nucleophiles in the presence of non-nucleophilic bases. The effects (electronic as well as steric) of the ortho-substituent (OH, NH₂, OMe, Me, Et, F, Cl and Br) on the course of the reaction have been investigated, determining their influence on yields and product ratios (2o/3o). An analysis of ¹³C NMR and MS spectra of 2o and 3o has been carried out. Ab initio computations on 2of, 2oi, 3of and 3oi at DFT level have furnished informations on their geometry and stability in the gas phase, thus allowing to assign a role to their stability on the course of the reaction as well as on some EI-MS results.