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1.
Natarajan Sampathkumar Arumugam Murugesh Subramaniam Parameswaran Rajendran 《Journal of heterocyclic chemistry》2016,53(3):924-928
The Vilsmeier Haack heterocyclization of 2‐aryl amino‐4‐phenyl quinolines quinoline yielded the hitherto unknown 5‐phenyl‐dibenzo[b,g][1,8]naphthyridines in quantitative yield. The synthesis of aryl amines was achieved by the action of anilines on 2‐chloro‐4‐phenyl quinoline, which in turn was sourced through the combes reaction of benzoyl acetanilides. 相似文献
2.
The reaction of dehydroacetic acid with iodosobenzene in combination with Vilsmeier–Haack reagent offers a new and convenient method for C‐C bond cleavage with the formation of 3‐chloro‐4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one. 相似文献
3.
A simple and concise approach for the synthesis of a series of new heterocyclic systems of 2‐(benzofuran‐2‐yl)benzo[h]quinoline‐3‐carboxylic acid derivatives ( 3a–3g ) is described. The synthetic strategy features the one‐pot reaction of ethyl 2‐(chloromethyl)benzo[h]quinoline‐3‐carboxylate ( 2 ) with various substituted salicylaldehydes as well as 2‐hydroxy‐1‐naphthaldehyde as a key step. The substrate 2 was prepared in good yield by a mild, efficient and direct reaction of 1‐naphthylamine ( 1 ) with Vilsmeier‐Haack reagent. The structures of all the new compounds were identified by spectral data and elemental analysis. 相似文献
4.
Vicente Samano Virgil L. Styles Joseph H. Chan 《Journal of heterocyclic chemistry》2000,37(1):183-185
This paper describes the synthesis of 2‐amino‐5‐[(4‐chlorophenyl)thio]‐4‐morpholinopyrimidine (BW 394U, compound 4 ), a potential antisenility agent. The key intermediates 3a/3b were obtained from an in situ‐generated Vilsmeier‐Haack reagent that simultaneously protected the 2‐amino group prior to further manipulations. Displacement of the chloro group in 3a gave 4 in 40% yield and 4‐dimethylamino analogue 5. However, displacement of 3b with morpholine followed by treatment with aqueous base gave 4 in 74% yield. 相似文献
5.
Yanyan Huang Ying Feng Wensheng Gao Chao Zhang Ligong Chen 《Journal of heterocyclic chemistry》2016,53(2):437-440
Laquinimod, 5‐chloro‐1,2‐dihydro‐N‐ethyl‐4‐hydroxy‐1‐methyl‐2‐oxo‐N‐ phenyl‐3‐quinoline carboxamide, is an oral drug in clinical trials for the treatment of multiple sclerosis. An efficient synthetic method for laquinimod from 2‐amino‐6‐chlorobenzoic acid via four steps was established. The overall yield of laquinimod is up to 82% as compared with 70% reported in literature. It has also been demonstrated that green reagent dimethyl carbonate is not suitable for the N‐methylation of 5‐chloroisatoic anhydride owing to the ring‐cleavage reaction induced by the generated methanol. The ring‐cleavage by‐products were isolated and characterized by 1H‐NMR and 13C‐NMR. In addition, in the study of laquinimod derivatives, we found that 5‐chloro‐1,2‐dihydro‐N‐ethyl‐4‐hydroxy‐1‐methyl‐2‐oxo‐N‐phenyl‐3‐quinoline carboxamide (laquinimod) was obtained in much higher yield than 7‐chloro‐1,2‐dihydro‐N‐ethyl‐4‐hydroxy‐1‐methyl‐2‐oxo‐N‐phenyl‐3‐quinoline carboxamide under the same reaction conditions, and it is possibly attributed to a neighboring group effect. 相似文献
6.
Roberta Costi Roberto Di Santo Marino Artico Silvio Massa 《Journal of heterocyclic chemistry》2002,39(1):81-90
The synthesis of derivatives of 2,3‐dihydroimidazo[1,5,4‐ef][1,2,5]benzothiadiazepin‐6(4H,7H)‐thione 1,1‐dioxide is reported starting from N‐substituted ethyl 2‐(5‐chloro‐2‐nitrobenzenesulfonamido)‐2‐alkyl‐acetates. Fundamental steps of the synthetic pathway were: i) intramolecular cyclization of N‐substituted 2‐(2‐amino‐5‐chlorobenzenesulfonamido)‐2‐alkylacetic acids in the presence of N‐(3‐dimethyl‐aminopropyl)‐N′‐ethyl carbodiimide hydrochloride‐N,N‐dimethylaminopyridine complex; ii) building of imidazole ring from 2‐alkyl‐8‐chloro‐2,3‐dihydro‐3‐methyl‐1,2,5‐benzothiadiazepin‐4(5H)‐one 1,1‐dioxide to achieve 2‐alkyl‐9‐chloro‐2,3‐dihydro‐3‐methylimidazo[1,5,4‐ef][1,2,5]benzothiadiazepin‐6(4H,7H)‐one 1,1‐dioxide; iii) preparation of thiocarbonyl derivative by treatment with Lawesson's reagent. Introduction of a 3‐methyl‐2‐butenyl chain at position 2 of above imidazobenzothiadiazepinone required protection at the 7 position with thermally removable tert‐butoxycarbonyl moiety, due to the fact that alkylation of unprotected structure proved to be regioselective for the 7 position. 相似文献
7.
The Synthesis of New Heterocycles Using 2‐(4‐Chloro‐1,3‐dihydro‐3,3,7‐trimethyl‐2H‐indol‐2‐ylidene) Propanedial 下载免费PDF全文
Maryam Alyari Mehdi M. Baradarani Arash Afghan John A. Joule 《Journal of heterocyclic chemistry》2014,51(3):854-859
4‐Chloro‐2,3,3,7‐tetramethyl‐3H‐indole (an indolenine) was produced by the reaction of 5‐chloro‐2‐methylphenylhydrazine hydrochloride with 3‐methylbutan‐2‐one via Fischer reaction. Exposure of the indolenine to the Vilsmeier reagent at 50°C produced a β‐diformyl compound, 2‐(4‐chloro‐1,3‐dihydro‐3,3,7‐trimethyl‐2H‐indol‐2‐ylidene)propanedial. This dialdehyde was reacted with arylhydrazines, acetamidinium chloride, urea, thiourea, guanidinium chloride, and cyanoacetamide to give various 5‐membered and 6‐membered heterocyclic products, each carrying a 4‐chloro‐3,3,7‐trimethyl‐3H‐indol‐2‐yl unit as a substituent, in excellent yields. 相似文献
8.
F. Aneesa K. C. Rajanna M. Venkateswarlu K. Rajendar Reddy Y. Arun Kumar 《国际化学动力学杂志》2013,45(11):721-733
Vilsmeier–Haack (VH) formylation reactions with acetophenones are sluggish in acetonitrile medium even at elevated temperatures. However, millimolar concentrations of transition metal ions such as Cu(II), Ni(II), Co(II), and Cd(II) were found to exhibit efficient catalytic activity in Vilsmeier–Haack Reactions with acetophenones. Reactions are accelerated remarkably in the presence of transition metal ions. The VH reactions followed second order kinetics and afforded acetyl derivatives under kinetic conditions also irrespective of the nature of oxychloride (POCl3 or SOCl2) used for the preparation of VH reagent along with DMF. On the basis of UV–vis spectroscopic studies and kinetic observations, participation of a ternary precursor [M(II) S (VHR)] in the rate‐limiting step has been proposed to explain the mechanism of the metal ion–catalyzed VH reaction. 相似文献
9.
K. C. Rajanna M. Venkateswarlu M. Satish Kumar U. Umesh Kumar G. Venkateshwarlu P. K. Saiprakash 《国际化学动力学杂志》2013,45(2):69-80
Vilsmeier–Haack (VH) benzoylation reactions with benzaldehydes and acetophenones in acetonitrile medium obeyed second‐order reaction kinetics. Under kinetic conditions, the reactions afforded benzoyl derivatives irrespective of the nature of oxychloride (POCl3 or SOCl2) used for the preparation of VH reagent along with benzamide. The present finding is advantageous to understand the nature of reactive species as well as the mechanism of benzoylation. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 45: 69–80, 2013 相似文献
10.
The crystal structures of N‐aryl‐1,2,3,4‐tetrahydro‐3,3‐dimethyl‐2,4‐quinolinediones bearing methoxy‐ ( 1 ), methyl‐ ( 2 ), and chloro‐ ( 3 ) substituents in 2′‐position of the phenyl ring have been determined by X‐ray crystal structure analysis. The heterocyclic ring in 1–3 adopts an envelope conformation, with the smallest ring puckering in the ortho‐chloro derivative 3 . The N‐aryl ring is almost perpendicular with respect to the quinoline‐2,4‐dione ring. The corresponding dihedral angle values are 83.2(1)°, 80.0(9)°, and 83.4(2)° in 1, 2 and 3 , respectively. The hydrogen bond of C H⋅⋅⋅O type joins the molecules of the ortho‐methoxy derivative 1 into dimers. The supramolecular structure also contains two C H⋅⋅⋅π interactions that link the hydrogen‐bonded dimers into sheets. In ortho‐methyl derivative 2 , one C H⋅⋅⋅π interaction generates infinite chains, whereas two C H⋅⋅⋅O hydrogen bonds and three C H⋅⋅⋅π interactions in the ortho‐chloro derivative 3 form three‐dimensional framework. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:325–331, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20436 相似文献
11.
Freddy H. Havaldar Ganesh B. Mule Bhushan V. Dabholkar 《Journal of heterocyclic chemistry》2013,50(4):828-837
Homophthalic anhydride 1 reacts with different aromatic amines to produce N‐substituted homophthalimides 2 under microwave irradiation. A rapid microwave‐assisted chemical synthesis of condensed 4‐substituted furo[2,3‐c]isoquinoline‐1,5(2H,4H)‐diones 3 and 5‐substituted‐2,3‐dihydro‐1H‐pyrano[2,3‐c]isoquinoline‐1,6(5H)‐diones 4 involving the condensation of a variety of alkanoyl chlorides with 2‐arylisoquinoline‐1,3‐diones 2 in the presence of base and aprotic solvent is described for the first time. By contrast, the facile ring opening reaction of furo[2,3‐c]isoquinoline‐1,5(2H,4H)‐dione 3 with Vilsmeier–Haack reagent under microwave irradiation yielded the α‐β unsaturated carboxyaldehyde 5 . This novel and clean one‐pot methodology, which is characterized by very short reaction time and easy workup procedure, can be exploited to generate some novel condensed isoquinoline derivatives. 相似文献
12.
《Journal of heterocyclic chemistry》2018,55(4):1002-1009
Twelve novel substituted 2‐chloroquinoline‐3‐carboxamide derivatives were prepared from acetanilides using the Vilsmeier–Haack reaction, producing 2‐chloro‐3‐carbaldehyde quinolines, followed by oxidation of the 3‐carbaldehyde to the carboxylic acid and coupling this group with various anilines. The structures of the synthesized compounds were confirmed by NMR, mass spectrometry, and single crystal X‐ray diffraction. The chemical shifts of H‐5 and H‐8 were shown to be influenced by the substituent at C‐6. The substituent at C‐6 was also seen to affect the chemical shift of C‐5, C‐7, and C‐8, with C‐5 and C‐7 being more shielded in 5j (F substituted) in comparison with 5g (Cl substituted) and 5d (CH3 substituted). The compounds showed weak activity in the mM range against Gram‐positive and Gram‐negative bacteria of which 5b , 5d , and 5f showed the best activity with minimum bactericidal concentration values for 5b being 3.79 mM against methicillin‐resistant Staphylococcus aureus and 5d and 5f having minimum bactericidal concentration values of 3.77 and 1.79 mM against S. aureus ATCC 25923, respectively. 相似文献
13.
Vilsmeier–Haack‐type cyclization of 1H‐indole‐4‐propanoic acid derivatives was examined as model construction for the A–B–C ring system of lysergic acid ( 1 ). Smooth cyclization from the 4 position of 1H‐indole to the 3 position was achieved by Vilsmeier–Haack reaction in the presence of K2CO3 in MeCN, and the best substrate was found to be the N,N‐dimethylcarboxamide 9 (Table 1). The modified method can be successfully applied to an α‐amino acid derivative protected with an N‐acetyl function, i.e., to 27 (Table 2); however, loss of optical purity was observed in the cyclization when a chiral substrate (S)‐ 27 was used (Scheme 5). On the other hand, the intramolecular Pummerer reaction of the corresponding sulfoxide 20 afforded an S‐containing tricyclic system 22 , which was formed by a cyclization to the 5 position (Scheme 3). 相似文献
14.
The synthesis of novel 1,6‐naphthyridines 6 with potential activity against tuberculosis is described using the reaction sequence 2←4←6. Depending on the ring N‐substitution of the 4‐alkylamino‐6‐methyl‐2(1H)‐pyridones 1 and 2 the electrophilic attack of the Vilsmeier reagent gives rise to the formation of the exocyclic N‐formyl derivatives 3 from 1 and the corresponding 3‐carbaldehydes 4 from 2. 1,2‐Dihydro‐2‐imino‐7‐methyl‐1,6(6H)‐naphthyridin‐5‐ones 6a‐j are prepared by the Knoevenagel reaction of 4 with CH‐acidic nitriles 5. These reactions are carried out using a comparative study of conventional conditions (room temperature or reflux) versus microwave irradiation. 相似文献
15.
Vikas S. Padalkar Kiran R. Phatangare N. Sekar 《Journal of heterocyclic chemistry》2013,50(4):809-813
Novel 2‐{4‐[1‐(pyridine‐2‐yl)‐1H‐pyrazol‐3‐yl] phenyl}‐2H‐naphtho [1,2‐d] [1,2,3] triazolyl fluorescent derivatives were synthesized from p‐nitrophenylacetic acid and 2‐hydrazino pyridine through Vilsmeier–Haack and diazotization reactions. Photophysical properties were evaluated, and results show that compounds have good fluorescence quantum yields. Thermal analysis showed that they are reasonably stable. The structures of the compounds were confirmed by FT‐IR, 1H NMR, 13C NMR, and mass spectral and elemental analysis. 相似文献
16.
Lingam Venkata Reddy Mohan Kethavath Mamatha Nakka Syed Sultan Beevi Lakshmi Narasu Mangamoori Khagga Mukkanti Sarbani Pal 《Journal of heterocyclic chemistry》2012,49(1):80-87
Functionalization of quinoline aldehydes, derived from nimesulide framework was carried out using Morita–Baylis–Hillman (MBH) chemistry. A number of novel quinoline‐based diverse MBH adducts was prepared via the reaction of derivatives of 2‐chloroquinoline‐3‐carbaldehyde and various activated alkenes in good yields. Many of these compounds were found to be potent when tested against human prostate cancer (Pc‐3) cell line in vitro. Among all the compounds tested N‐(2‐chloro‐3‐(2‐cyano‐1‐hydroxyallyl)‐7‐phenoxyquinolin‐6‐yl)formamide (IC50 = 1.2 μg mL?1) was identified as the most potent compound in this series. J. Heterocyclic Chem., (2012). 相似文献
17.
Anita Guesdon Alain Fogain‐Ninkam Bernard Decroix Pierre Netchitaïlo 《Journal of heterocyclic chemistry》2001,38(6):1441-1445
1‐(1,3‐Dioxo‐1,3‐dihydro‐2H‐isoindol‐2‐yl)‐1H‐pyrrol‐2 carbaldehyde 4 was synthesized by Vilsmeier‐Haack reaction from 2‐(pyrrol‐1‐yl) phthalimide. Reduction of 4 by sodium borohydride, or action of Grignard reagents on 4 led to the corresponding alcohols 5 which were cyclized to pyrroloxadiazino isoin‐doles 1 by heating in the presence of silica gel. Transformation of the hydroxylactam 6 with acetic acid derivatives led to the esters 7 which gave, after saponification, pyrroloxa(or thia)diazepinoisoindolones 2 by intramolecular cyclization. 相似文献
18.
Bromination of aromatic hydrocarbons is triggered by Vilsmeier–Haack reagent [N,N-dimethyl formamide (DMF–POCl3 system)] in the presence of KBr or N-bromosuccinimide (NBS) under solvent-free conditions by grinding the reactants in a mortar with a pestle. The reactions afforded corresponding bromo derivatives in very good yield with high regioselectivity. The results are comparable with those obtained under reflux conditions. 相似文献
19.
A new Schiff's base and 2-azetidinone derivatives obtained via the corresponding 3-benzo [4,5] imidazo [2,1-b] thiazol-3-yl-chromen-2-one by Vilsmeier–Haack formylation scaffold is described. Our design is aimed at obtaining new triheterocyclic and tetraheterocyclic derivatives. 相似文献
20.
A one‐pot synthesis of oxime derivatives 3a–3f of 1‐phenyl‐3‐arylpyrazole‐4‐carboxaldehydes has been accomplished by the Vilsmeier–Haack reaction of acetophenone phenylhydrazones 1a–1f under a new workup procedure. 相似文献