- Regioselective n-alkylation of 4-formylimidazole
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We describe here a high yield and highly regioselective N-alkylation of 4-formylimidazole via reversible Michael Reaction.
- Su, Qiaogong,Wood, Jeffery L.
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- Urocanic acid photobiology. Purine-assisted photooxidation to 1H- imidazole-4(5)-carboxaldehyde
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Urocanic acid undergoes photooxidative cleavage at the acrylic acid side chain to afford imidazole carboxaldehyde. The reaction is accelerated in the presence of purines. Evidence is presented that the photooxidation involves a reaction of the UA radical cation and ground state molecular oxygen.
- Mohammad,Kasper,Morrison
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Read Online
- A simple and efficient synthesis of N-protected imidazole-4-carbaldehyde
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Successive addition of BuLi, triethylsilyl chloride, s-BuLi and DMF to 1- (N,N-dimethylsulfamoyl)imidazole (1) yields pure 1-(N,N-dimethylsulfamoyl)- 2-(triethylsilyl)imidazole-4-carbaldehyde (2) as judged by 1H NMR spectroscopy. Treatment of 2 with 2 N HCl leads to free imidazole-4- carbaldehyde (3) (overall yield 70.2%).
- Winter,Retey
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Read Online
- Method for preparing 1H-imidazole-4-carbonitrile
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The invention discloses a method for preparing 1H-imidazole-4-carbonitrile, and particularly relates to the technical field of fine chemical product preparation. The method for preparing 1H-imidazole-4-carbonitrile comprises the following steps: step (1) oxidation reaction: performing oxidation on 4-hydroxymethylimidazole to obtain 1H-imidazole-4-carboxaldehyde; step (2) oximation reaction: performing oximation reaction on the 1H-imidazole-4-carboxaldehyde prepared in the step (1) to obtain 4-formaldoximido imidazole; and step (3) dehydration reaction: performing dehydration reaction on the 4-formaldoximido imidazole prepared in the step (2) to obtain 1H-imidazole-4-carbonitrile. The method provided by the invention has the advantages of reducing many steps due to intermediates are not purified from the beginning of the reaction to the end of the process, reducing energy consumption due to high and low temperature equipment is not used, reducing environmental pollution due to acidic wastewater is not generated, and having a high yield of products; the invention proposes a complete process route for synthesizing 1H-imidazole-4-carbonitrile by using 4-hydroxymethylimidazole as a rawmaterial; and the method is simple in process and easy to realize industrial production.
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Paragraph 0034; 0043-0049
(2019/02/26)
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- Synthesis method of 1H-imidazole-4-carboxylic acid
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The invention discloses a synthesis method of 1H-imidazole-4-carboxylic acid. The method comprises steps as follows: (1) a hydrochloric acid solution is added to a reaction kettle, chromium trioxide is added under the stirring condition, the mixture is stirred uniformly and heated to 40-50 DEG C, pyridine is dropwise added, the mixture is stirred to react for 2-3 h after pyridine is dropwise added, PCC (pyridinium chlorochromate) is prepared, TiO2 is added, a dichloromethane solution of 4-methylimidazole is dropwise added under the stirring condition, the mixture is subjected to a reaction at40-50 DEG C for 3-4 h, then, filtration and centrifugation are performed, an organic layer is collected, reduced pressure distillation is performed, and 1H-imidazole-4-formaldehyde is prepared; (2) prepared 1H-imidazole-4-formaldehyde and dichloromethane are mixed, the obtained mixture is heated to 40-50 DEG C, KMnO4 is added, the mixture is mixed uniformly and stirred for a reaction for 3-4 h, filtration, reduced pressure distillation and recrystallization are performed, and 1H-imidazole-4-carboxylic acid is prepared. The synthesis method is simple to operate and mild in condition, fewer by-products are produced, the product purity is high and the product yield is higher.
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Paragraph 0021; 0028; 0035; 0042; 0049
(2018/05/16)
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- Hydrazinyl-Substituted Heteroaryl Compounds and Methods for Producing a Conjugate
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The present disclosure provides conjugate structures and hydrazinyl-substituted heteroaryl compounds used to produce these conjugates. The disclosure also encompasses methods of production of such conjugates and compounds, as well as methods of using the same.
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Paragraph 0540-0542
(2017/09/29)
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- Halogen–metal exchange on bromoheterocyclics with substituents containing an acidic proton via formation of a magnesium intermediate
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A selective and practical bromine–metal exchange on bromoheterocyclics bearing substituents with an acidic proton under non-cryogenic conditions was developed by a simple modification of an existing protocol. Our protocol of using a combination of i-PrMgCl and n-BuLi has not only solved the problem of intermolecular quenching that often occurred when using alkyl lithium alone as the reagent for halogen–lithium exchange, but also offered a highly selective method for performing bromo–metal exchange on dibrominated arene compounds through chelation effect.
- Tian, Qingqiang,Shang, Suqin,Wang, Huajun,Shi, Guoqiang,Li, Zhiyao,Yuan, Jianyong
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supporting information
(2017/12/05)
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- An expedient osmium(vi)/K3Fe(CN)6-mediated selective oxidation of benzylic, allylic and propargylic alcohols
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A chemoselective osmium(vi) catalyzed oxidation of benzylic, allylic and propargylic alcohols using K3Fe(CN)6as a secondary oxidant is described. This protocol is operationally simple and exhibits excellent chemoselectivity favouring the oxidation of benzylic alcohols over the aliphatic alcohols. A larger scale reaction was also found to be compatible. This journal is
- Fernandes, Rodney A.,Bethi, Venkati
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p. 40561 - 40568
(2015/02/18)
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- PRODUCTION METHOD OF IMIDAZOLE DERIVATIVES
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The present invention provides an advantageous production method of an imidazole derivative, which is suitable for industrial production. Compound (VI) is produced by reacting compound (I) with a Grignard reagent or a magnesium reagent, and a lithium reagent, and then reacting the resulting compound with compound (V).
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Page/Page column 34-35
(2013/02/28)
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- Design and synthesis of new 1,4-dihydropyridines containing 4(5)-chloro-5(4)-imidazolyl substituent as a novel calcium channel blocker
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New analogues of nifedipine, in which the ortho-nitro phenyl group at position 4 has been replaced by 4(5)-chloro-5(4)-imidazolyl substituent and which are able to interact with the receptor by hydrogen binding were designed, synthesized, and evaluated as calcium channel antagonists. The designed dihydropyridines were synthesized using the Hantzsch condensation and evaluated as calcium channel antagonists using the high K+ contraction of guineapig ileal longitudinal smooth muscle. A docking study was performed using the AutoDock4 program, and QSAR equations were obtained using multilinear regression. Our computational studies indicated that the oxygen of the ester (O10) and the N3′ of the imidazole ring form a hydrogen bonding interaction with the NH of HIS 363 and NH of LYS354, respectively, and that the sum of the BEHp5 and RDF075p are the most significant descriptors. The results of calcium channel antagonist evaluation demonstrated that increasing the chain length in C3 and C5 ester substituents increased activity. The most potent compound was the bis-phenylpropyl ester (5l) derivative, in that it was more active than the reference drug nifedipine and that the bis-phenylethyl ester (5k) derivative had comparable activity with nifedipine. The present research revealed that the 4(5)-chloro-5(4)-imidazolyl moiety is a bioisoster of o-nitrophenyl in nifedipine and provided novel dihydropyridines with more activity as calcium channel antagonists.
- Iman, Maryam,Davood, Asghar,Nematollahi, Ali Reza,Dehpoor, Ahmad Rerza,Shafiee, Abbas
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scheme or table
p. 1417 - 1426
(2012/05/04)
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- Synthesis and anti-breast cancer activities of substituted quinolines
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Promising anti-breast cancer agents derived from substituted quinolines were discovered. The quinolines were readily synthesized in a large scale from a sequence of reactions starting from 4-acetamidoanisole. The Michael addition product was isolated as the reaction intermediate in the ring closing reaction of 4-amino-5-nitro-2-(3-trifluoromethylphenyloxy)anisole with methyl vinyl ketone leading to 6-methoxy-4-methyl-8-nitro-5-(3-trifluoromethylphenyloxy)quinoline (14). The amino function of 8-amino-6-methoxy-4-methyl-5-(3-trifluoromethylphenyloxy)quinoline, prepared from 14, was connected to various side chains via alkylation with N-(3-iodopropyl)phthalimide, Michael addition with acrylonitrile, and reductive amination with various heterocycle carboxaldehydes, such as imidazole-4-carboxaldehyde, thiophene-2-carboxaldehyde, and 2-furaldehyde. Effects of the substituted quinolines on cell viability of T47D breast cancer cells using trypan blue exclusion assay were examined. The results showed that the IC50 value of 6-methoxy-8-[(2-furanylmethyl)amino]-4-methyl-5-(3-trifluoromethylphenyl oxy)quinoline is 16 ± 3 nM, the lowest IC50 out of all the quinolines tested. IC50 values of three other quinolines are in the nanomolar range, a desirable range for pharmacological testing.
- Shi, Aibin,Nguyen, Thu A.,Battina, Srinivas K.,Rana, Sandeep,Takemoto, Dolores J.,Chiang, Peter K.,Hua, Duy H.
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body text
p. 3364 - 3368
(2009/04/11)
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- PHARMACEUTICAL COMPOUNDS
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Fused pyrimidines of formula (I); wherein A represents a thiophene or furan ring; n is 1 or 2; R1 is a group of formula (II); wherein m is 0 or 1; R30 is H or C1-C6 alkyl; R4 and R5 form, together with the N atom to which they are attached, a 5- or 6-membered saturated N-containing heterocyclic group which includes 0 or 1 additional heteroatoms selected from N, S and O, which may be fused to a benzene ring and which is unsubstituted or substituted; or one of R4 and R5 is alkyl and the other is a 5- or 6-membered saturated N-containing heterocyclic group as defined above or an alkyl group which is substituted by a 5- or 6-membered saturated N-containing heterocyclic group as defined above; R2 is selected from formula (a); wherein R6 and R7 form, together with the nitrogen atom to which they are attached, a morpholine, thiomorpholine, piperidine, piperazine, oxazepane or thiazepane group which is unsubstituted or substituted; and formula (b); wherein Y is a C2-C4 alkylene chain which contains, between constituent carbon atoms of the chain and/or at one or both ends of the chain, 1 or 2 heteroatoms selected from O, N and S, and which is unsubstituted or substituted; and R3 is an indazole group which is unsubstituted or substituted; and the pharmaceutically acceptable salt thereof have activity as inhibitors of P13K and may thus be used to treat diseases and disorders arising from abnormal cell growth, function or behaviour associated with P13 kinase such as cancer, immune disorders, cardiovascular disease, viral infection, inflammation, metabolism/endocrine disorders and neurological disorders. Processes for synthesizing the compounds are also described.
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Page/Page column 87
(2008/06/13)
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- PHARMACEUTICAL AND COSMETIC COMPOSITIONS COMPRISING UROCANIC ACID DERIVATIVES AS RADICAL SCAVENGERS OR ANTIOXIDANTS
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Upon exposure to UVB, the epidermal component trans-urocanic acid is not only photoisomerized into cis-urocanic acid, but will also, at least in part, be photooxidized into urocanic acid oxidation products. We hypothesized that urocanic acid oxidation products can mimic UV-induced systemic immunosuppression comparable to the suppressive properties already established for cis-urocanic acid. A crude mixture of urocanic acid oxidation products showed a significant suppression of the sensitization phase of the systemic contact hypersensitivity response to picryl chloride. Three of the urocanic acid oxidation products were selected for this study: imidazole-4-carboxylic acid, imidazole-4-carboxaldehyde and imidazole-4-acetic acid. Effects on the sensitization-, elicitation- and post-elicitation phase of contact hypersensitivity to picryl chloride in BALB/c mice were studied and compared to the effects of cis-urocanic acid. Imidazole-4-carboxaldehyde was equally effective at suppressing the sensitization phase as cis-urocanic acid. The triplet combination of the imidazoles showed more pronounced suppression than that induced by cis-urocanic acid. The most effective compounds for the suppression of the elicitation phase appeared to be imidazole-4-acetic acid and cis-urocanic acid. Significant suppression of the post-elicitation phase was only obtained with the triplet combination of imidazole-4-carboxaldehyde, imidazole-4-carboxylic acid and imidazole-4-acetic acid, which combination appeared to be effective at all three tested phases, Because these three urocanic acid oxidation products are present in UVB-exposed human stratum corneum, these compounds may play a role in UVB-induced immunosuppression.
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Page/Page column 5; 14; 15; 22
(2008/06/13)
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- Preparation of (fluoromethyl)- and (difluoromethyl)imidazoles
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2-(Fluoromethyl)- and 2-(difluoromethyl)imidazoles, and 4-(fluoromethyl)- and 4-(difluoromethyl)imidazoles have been prepared by deoxyfluorination of (hydroxymethyl)imidazole or formylimidazole precursors.
- Dolensky, Bohumil,Kirk, Kenneth L.
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p. 1335 - 1344
(2007/10/03)
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- New synthetic routes to pyrrolo-[1,2-a]- and -[1,2-c]-imidazol-5-ones by flash vacuum pyrolysis
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1-Substituted and 1,3-disubstituted pyrrolo[1,2-c]imidazol-5-ones 25-27 have been made in fair to excellent yield by flash vacuum pyrolysis (FVP) of the Meldrum's acid precursors 11-13. FVP of the appropriate propenoate precursor 23, 22 and 18-20 gives pyrrolo[1,2-c]imidazol-5-one 2, pyrrolo[1,2-a]-imidazol-5-one 3 and their 6-methyl derivatives 28-30 respectively in 32-90% yield. The mechanism of the propenoate pyrolyses involves rate determining E to Z isomerisation of the alkene followed by elimination of an alcohol and electrocyclisation to the fused ring products.
- McNab, Hamish,Thornley, Craig
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p. 2203 - 2209
(2007/10/03)
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- Preparation and structure determination of 1-benzyl-, 1-methyl- and 1H-5-[(2-nitro-2-phenyl)ethenyl]imidazoles
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1-R-5-[(2-Nitro-2-phenyl)ethenyl]imidazoles (R = Bn, Me, H) 6a,b,c were synthesized by the Knoevenagel reaction of the corresponding aldehydes 4a,b,c with phenylnitromethane 5. The E-isomers 6a,b,c were precipitated from the reaction mixture as crystalline compounds in 89, 81 and 60% yields, respectively. Traces of the Z-isomers 6a'b',c' were found in the reaction mixtures but could be obtained in a ratio of 4:3 from the E-form with UV irradiation. The E-forms were more stable and the Z-isomers changed again to the E-isomers in several weeks.
- Aulaskari, Paula,Ahlgren, Markku,Rouvinen, Juha,Vainiotalo, Pirjo,Pohjala, Esko,Vepsaelaeinen, Jouko
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p. 1345 - 1354
(2007/10/03)
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- Synthese Stereoselective de la Girolline
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Desaminogirollines syn 2'S,3'S and 2'R,3'R have been prepared from N1-camphosulfonamide 4-carboxaldehyde imidazole and their diastereomeric derivatives have been separated.The stereoselective synthesis of chiral natural girolline has been achieved from D(-)arabinose : this ose is condensed with formamidine acetate to obtain a 4(5)--imidazole; the side-chain is chlorinated before being aminated via an azido compound and the 2-amino group of girolline is obtained by rhodium catalytic reduction of the 2-diazo derivative.Key Words: girolline synthesis; 2-aminoimidazole; D(-)-arabinose; 4(5)imidazole; rhodium reduction.
- Ahond, Alain,Mourabit, Ali Al,Bedoya-Zurita, Manuel,Heng, Richard,Braga, Raquel Marques,et al.
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p. 4327 - 4346
(2007/10/02)
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- 7-oxabicycloheptane imidazole prostaglandin analogs useful in the treatment of thrombotic and vasospastic disease
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7-Oxabicycloheptane imidazole prostaglandin analogs are provided which are useful in treating thrombotic and vasospastic disease and have the structural formula STR1 wherein m is 0, 1, 2, 3 or 4; n is 1, 2 or 3; and p is 1, 2 or 3; Z is --CH=CH--, --CH2 CH2 -- or STR2 wherein Y is 1 or a single bond; R is CO2 H, CO2 lower alkyl, CO2 alkali metal, CONHSO2 R2 (wherein R2 is lower alkyl or aryl) or --CH2 -5-tetrazolyl; A is CHOH, C=O, STR3 (wherein R3 is H or lower alkyl), or a single bond; R1 is lower alkyl, aryl, cycloalkyl or H, R1 can be H only when A is a single bond.
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- Synthesis of Pyrroloimidazol-5-one, Pyrroloimidazol-5-one and Pyrrolopyrazol-6-one (Three Isomeric Azapyrrolizinones), by Pyrolysis of Meldrum's Acid Derivatives
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Reaction of Meldrum's acid with the imidazole- and pyrazole-carbaldehydes (9)-(11) gave the condensation products (6), (7a), and (8) which were pyrolysed in the gas phase to give the title azaanalogues (2)-(4) of pyrrolizin-3-one (1), as air-sensitive yellow solids.
- McNab, Hamish
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p. 653 - 656
(2007/10/02)
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- Synthesis of 4(5)-Acyl-, 1-Substituted 5-Acyl, and 1-Substituted 4-Acyl-1H-imidazoles from 4-Aminoisoxazoles
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4-Aminoisoxazoles can be acylated with a wide variety of activated carboxylic acids.Hydrogenation of the resulting amides gives α-(acylamino)enaminones, which cyclize to 4(5)-acylimidazoles upon treatment with base.This method allows for the synthesis of acylimidazoles with a wide range of substituents at C-2.Utilization of N-substituted 4-aminoisoxazoles in the same sequence of reactions yields 1-substituted 5-acylimidazoles, a substitution pattern not otherwise easily prepared.Treatment of α-(acylamino)enaminones, derived from N-unsubstituted isoxazoles, with primary amines leads to incorporation of the amine at the β-position with concomitant expulsion of ammonia.This sequence efficiently yields 1-substituted and 1,2-disubstituted 4-acylimidazoles but does not give satisfactory yields of 5-substituted 4-acylimidazoles due to steric inhibition of the amine exchange.
- Reiter, Lawrence A.
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p. 2714 - 2726
(2007/10/02)
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- Mass Spectrometry of Imidazole-4(5)-carboxaldehyde and Some 1-Methyl and Nitro Derivatives
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The mass spectra of imidazole-4(5)-carboxaldehyde, its two 1-methyl derivatives, 4(5)-nitroimidazole, 5(4)-nitroimidazole-4(5)-carboxaldehyde and 1-methyl-5-nitroimidazole-4-carboxaldehyde are presented and discussed in comparison with those of other imidazole-carboxaldehydes and nitroimidazoles earlier reported.The imidazole-carboxaldehydes and their 1-methyl derivatives exhibit the characteristic fragmentation of aromatic aldehydes, and differences between the isomers can be observed.The nitroimidazoles show the fragmentation typical of aromatic nitrocompounds.In the o-nitroimidazole-carboxaldehydes, the typical losses of aldehydes do not occur, but primary ortho effects between the formyl and nitro groups give rise to important fragmentation routes.In their 1-methyl derivatives, the presence of the methyl group adjacent to the nitro group originates additional double and secondary ortho effects.For some of these transformations, fragmentation mechanisms are proposed.
- Cert, Arturo,Delgado-Cobos, Pedro,Perez-Lanzac, Mariana Trujillo
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p. 499 - 506
(2007/10/02)
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- 4-Lithio-1-tritylimidazole as a Synthetic Intermediate. Synthesis of Imidazole-4-carboxaldehyde
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Reaction of 4-iodo-1-tritylimidazole with n-butyllithium at -79 deg, followed by rapid quenching of the reaction mixture with DMF, gives good yields of 1-tritylimidazole-4(5)-carboxaldehyde, the isolation of which demonstrates the intermediacy of 4-lithio-1-tritylimidazole.This species should be destabilized by repulsive interaction of the negative charge on C-4 with the adjacent lone pair electrons on N-3 (the ALP effect).The isolation of 1-tritylimidazole-4(5)-carboxaldehyde in good yield and the versatility of the aldehyde functionality make 4-lithio-1-tritylimidazole a useful synthetic intermediate.
- Kirk, Kenneth L.
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- Synthesis and Photocylization of some 4-(5)Arylethenylimidazoles
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The synthesis of eleven 4-(5)arylethenylimidazoles and their separation into cis and trans isomers is described.Ir, uv, nmr, and mass spectrometric data of the compounds are given.The photocyclization of the unsubstituted and p-substituted compounds is reported.
- Lindberg, Gerd,Stensioe, Karl-Erland,Wahlberg, Kerstin
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p. 679 - 683
(2007/10/02)
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