Search

An improved pharmacophore model, molecular properties, geometric analyses, and SAR led to synthesize oxazolo/thiazolo-[3,2-a]-pyrimidin-3(2H)-one, and 1,5-dihydroimidazo-[1,2-a]-pyrimidin-3(2H)-one derivatives exhibiting potent anti-hypertensive activity. The 6-ethoxycarbonyl-2,7-dimethyl-5-phenyl-1,5-dihydroimidazo[3,2-a]pyrimidin-3(2H)-one (4g), and 6-ethoxycarbonyl-2,7-dimethyl-5-(3-methyl-phenyl)-1,5-dihydroimidazo[3,2-a]pyrimidin-3(2H)-one (4h) showed significant reduction in mean arterial blood pressure (MABP, mm/Hg) of 79.78%, and 92.95% in 6 and 12 h durations, respectively, at 1.5 mg/kg body-weight dose, while at 3.0 mg/kg body-weight dose, the MABP reduction was achieved at 95.46%, and 92.02%, respectively, in 6 and 12 h durations, as compared to the standard drug, nifedipine., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

We describe here the synthesis of libraries of novel 1-subtituted-5-aryl-1H-imidazole, 5-aryl-4-tosyl-4,5-dihydro-1,3-oxazole and 5-aryl-1,3-oxazole fragments via microwave (MW)-assisted cycloaddition of para-toluenesulfonylmethyl isocyanide (TosMIC) to imines and aldehydes. The compounds obtained were biologically evaluated in an AlphaScreen HIV-1 IN-LEDGF/p75 inhibition assay with six imidazole-based compounds (16c, 16f, 17c, 17f, 20a and 20d) displaying more than 50% inhibition at 10 µM, with IC 50 values ranging from 7.0 to 30.4 µM. Additionally the hypothesis model developed predicts all active scaffolds except 20d to occupy similar areas as the N-heterocyclic (A) moiety and two aromatic rings (B and C) of previously identified inhibitor 5. These results indicate that the identified compounds represent a viable starting point for their use as templates in the design of next generation inhibitors targeting the HIV-1 IN and LEDGF/p75 protein-protein interaction. In addition, the in vitro antimicrobial properties of these fragments were tested by minimum inhibitory concentration (MIC) assays showing that compound 16f exhibited a MIC value of 15.6 μg/ml against S. aureus, while 17f displayed a similar MIC value against B. cereus, suggesting that these compounds could be further developed to specifically target those microbial pathogens., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In the present work, a novel series of B-RAF kinase inhibitors having imidazo[2,1-b]oxazole scaffold was designed and synthesized based on the structures of the well-known B-RAF inhibitors. The twenty two final compounds were tested over A375 and SKMEL28 cell lines to determine the primary cytotoxic activity of these compounds, and their activities were compared with that of sorafenib as a standard. Compounds 11c, 11e, 11o, 11q, 11r, and 11u exhibited higher cellular activity compared to sorafenib with IC 50 values of 7.25, 8.03, 9.81, 8.47, 4.70, and 9.04 µM, respectively and 10.38 µM for sorafenib. In addition, the target compounds were screened for their anticancer activity by the NCI-60 cell line assay. Compounds 11v and 11u were the most active compounds with percent inhibition reached 95.99% for 11v and 87.03% for 11u over K562 cell line at 10 µM concentration. Compound 11v was selected for 5-dose test mode. Furthermore, the kinase inhibitory activities of 11a, 11c, 11e, 11i, 11o, 11q, 11r, 11u, and 11v were determined against wild-type B-RAF, V600E-B-RAF, and RAF1. Compound 11o was the most potent against V600E-B-RAF with IC 50 34 nM followed by 11q and 11u with IC 50 92 and 93 nM, respectively., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Targeted therapies for ER+/PR+ and HER2-amplified breast cancers have improved patient survival, but there are no therapies for triple negative breast cancers (TNBC) that lack expression of estrogen and progesterone receptors (ER/PR), or amplification or overexpression of HER2. Gene expression profiling of TNBC has identified molecular subtypes and representative cell lines. An extract of the Texas native plant Amyris texana was found to have selective activity against MDA-MB-453 cells, a model of the luminal androgen receptor (LAR) subtype of TNBC. Bioassay-guided fractionation identified two oxazole natural products with selective activity against this cell line. Conducted analog synthesis and structure-activity relationship studies provided analogs with more potent and selective activity against two LAR subtype cell line models, culminating in the discovery of compound 30 (CIDD-0067106). Lead compounds discovered have potent and selective antiproliferative activities, and mechanisms of action studies show they inhibit the activity of the mTORC1 pathway.

Covering: July 2012 to June 2015. Previous review: Nat. Prod. Rep., 2013, 30, 869-915The structurally diverse imidazole-, oxazole-, and thiazole-containing secondary metabolites are widely distributed in terrestrial and marine environments, and exhibit extensive pharmacological activities. In this review the latest progress involving the isolation, biological activities, and chemical and biogenetic synthesis studies on these natural products has been summarized.

CuI-catalyzed oxidative reaction of amidines with C60 using air as the oxidant has been exploited for the easy preparation of fulleroimidazole derivatives. Furthermore, this kind of CuI-catalyzed [3 + 2] reaction has also been successfully applied in the synthesis of fullerooxazole derivatives starting from amides for the first time. The substrate scope is broad, and the process is particularly cheap and simple.

Twenty-three naphthoimidazoles and six naphthoxazoles were synthesised and evaluated against susceptible and rifampicin- and isoniazid-resistant strains of Mycobacterium tuberculosis. Among all the compounds evaluated, fourteen presented MIC values in the range of 0.78 to 6.25 μg/mL against susceptible and resistant strains of M. tuberculosis. Five structures were solved by X-ray crystallographic analysis. These substances are promising antimycobacterial prototypes., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

A series of substituted 4-(2,6-dichlorobenzyloxy)phenyl thiazole, oxazole and imidazole derivatives were synthesized. The derivatives were screened for in vitro anti-tubercular activities against Mycobacterium tuberculosis H37Rv using the Microplate Alamar Blue Assay (MABA), and antibacterial activities with agar dilution method against clinical S. aureus, E. coli, S. pneumoniae and penicilin-resistant S. pneumoniae. Among 15 compounds, several thiazole derivatives exhibited good anti-tubercular activities with MIC values between 1 μM and 61.2 μM, and potent activities against S. pneumoniae with MIC values less than 0.134 μM. These studies suggest that the thiazole scaffold may serve as a new promising template for further elaboration as anti-tubercular and antibacterial drugs., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

A structure involving the absolute configuration of acinetobactin (1b) was clarified. It was reconfirmed that preacinetobactin (1a) produced 1b by a rearrangement reaction.

New combretastatin A analogues featuring oxazole or N-methylimidazole bridged Z-alkenes and halo- or amino-substituted A-rings were tested against various cancer cell lines and in testicular germ cell tumor xenografts in mice. Imidazoles with 3-halo-4,5-dimethoxy substituted A-rings and 3-amino-4-methoxy substituted B-rings (7b and 8b) were efficacious at nanomolar concentrations against cells of combretastatin A refractory HT-29 colon carcinoma, multidrug-resistant MCF-7/Topo breast carcinoma, and cisplatin-resistant 1411HP testicular germ cell tumor. They induced apoptosis and inhibited tubulin polymerization. While well tolerated by mice at high doses, these imidazoles initiated extensive intratumoral hemorrhage and regressions of highly vascularized 1411HP xenografts.

Two GFP analogues o-HBDI and o-HBMO have been designed and synthesized. The former shows no fluorescence while the latter shows strong fluorescence due to the formation of an intramolecular hydrogen-bond. At low temperatures, both molecules have strong fluorescence.

Various dihaloazoles can be monoarylated at a single C-X bond with high selectivity via Suzuki coupling. By changing the palladium catalyst employed, the selectivity can be switched for some dihaloazoles, allowing for Suzuki coupling at the other, traditionally less reactive C-X bond. These conditions are applicable to coupling of a wide variety of aryl-, heteroaryl-, cyclopropyl-, and vinylboronic acids with high selectivities and enable the rapid construction of diverse arrays of diarylazoles in a modular fashion.

The design and synthesis of a novel series of oxazole-, thiazole-, and imidazole-based inhibitors of IkappaB kinase (IKK) are reported. Biological activity was improved compared to the pyrazolopurine lead, and the expedient synthesis of the new tricyclic systems allowed for efficient exploration of structure-activity relationships. This, combined with an iterative rat cassette dosing strategy, was used to identify compounds with improved pharmacokinetic (PK) profiles to advance for in vivo evaluation.

Research on the therapeutic applications of the histamine H3 receptor (H3R) has traditionally focused on antagonists/inverse agonists. In contrast, H3R agonists have received less attention despite their potential use in several disease areas. The lower availability of H3R agonists not only hampers their full therapeutic exploration, it also prevents an unequivocal understanding of the structural requirements for H3R activation. In the light of these important issues, we present our findings on 4-benzyl-1H-imidazole-based H3R agonists. Starting from two high throughput screen hits (10 and 11), the benzyl side chain was altered with lipophilic groups using combinatorial and classical chemical approaches (compounds 12-31). Alkyne- or oxazolino-substituents gave excellent affinities and agonist activities up to the single digit nM range. Our findings further substantiate the growing notion that basic ligand sidechains are not necessary for H 3R activation and reveal the oxazolino group as a hitherto unexplored functional group in H3R research.

Design, synthesis and conformational analysis of few imidazole and oxazole as bioisosters of 4S-(-)-3-(4-chlorophenyl)-N-methyl-N'-[(4-chlorophenyl)-sulfonyl]-4-phenyl-4,5-dihydro-1H-pyrazole-1-caboxamidine (SLV-319) 2 is reported. Computer assisted conformational analysis gave a direct clue for the loss of CB1 antagonistic activity of the ligands without a fine docking simulation for the homology model.

[reaction: see text] We report highly efficient two-step procedures for the synthesis of 1,3-oxazole-, thiazole-, and imidazole-containing peptides on solid phase from dipeptides composed of C-terminal threonine, serine, cysteine, or diaminopropionic acid by using different cyclodehydration procedures followed or preceded by oxidation. The methods are compatible with Fmoc solid-phase peptide synthesis conditions and with N-Fmoc, N-Boc, N-Cbz, and N-Alloc protecting groups.

The preparation of substituted imidazoles, thiazoles, and oxazoles using traceless solid-phase sulfone linker strategy is described. Key steps involved are (i) sulfinate acidification, (ii) sulfinic acid condensation with aldehyde and amine, and (iii) traceless product release by a one-pot elimination-cyclization reaction. The elimination reaction was carried out in the presence of a thiazolium catalyst that facilitated the in situ formation of the alpha-ketoamide, which was subsequently converted to the corresponding imidazoles, oxazoles, and thiazoles by treatment with amines, PPh(3)/I(2) or Lawesson's reagent. A library of 18 compounds was synthesized.

Synthesis of novel 5-methylidene-1,2,3,5-tetrahydro[2,1-b]-quinazoline derivatives 2-4 with potential biological activities mediated by alpha-adrenergic and/or imidazoline receptors was performed by reacting 2-chloro-4,5-dihydroimidazole (1) with the corresponding 2-aminoacetophenones. Compound 2, which incorporates an enamine moiety, underwent a 1,3-dipolar cycloaddition reaction with the appropriate nitrones 5-9 to give 1,2,3,5-tetrahydro-imidazo[2,1-b]quinazolin-5,5'-spiro-2',3'-diphenylisoxazol-idines 10-14. Reactions of the title compounds 2 and 4 with dimethyl acetylene-dicarboxylate (DMAD) afforded dimethyl 2-(2,3-dihydroimidazo[2,1-b]quinazolin-5(1H)-ylidenemethyl)but-2-enedioates 15, 16. Imidazo[2,1-b]quinazoline 2 was further treated with acetyl chloride, benzoyl chloride and mesyl chloride to give the 1-substituted derivatives 17, 18 and 19, respectively. The structures of all new compounds obtained were confirmed by elemental analysis and spectral data (IR, (1)H- and (13)C-NMR) as well asX-ray crystallographic analysis of 3 and 18.

Nephrotoxicity of the agricultural fungicide N-(3,5-dichlorophenyl)succinimide (NDPS) in rats is believed to involve metabolism on the succinimide ring. To further investigate this hypothesis, we synthesized and tested the following NDPS analogues, which contain other cyclic imide rings and may therefore be metabolized differently than NDPS: 3-(3,5-dichlorophenyl)-2,4-oxazolidinedione (DCPO), 3-(3,5-dichlorophenyl)-2,4-imidazolidinedione (DCPI), 3-(3,5-dichlorophenyl)-1-methyl-2,4-imidazolidinedione (DCPM) and 3-(3,5-dichlorophenyl)-2,4-thiazolidinedione (DCPT). Male Fischer 344 rats were administered DCPO, DCPI, DCPM, DCPT (0.6 or 1.0 mmol/kg, i.p. in corn oil), NDPS (0.6 mmol/kg, i.p. in corn oil) or corn oil (4 ml/kg). As evidenced by diuresis, proteinuria, elevated blood urea nitrogen levels, increased kidney weights and proximal tubular damage, NDPS produced severe nephrotoxicity in the rats. In contrast, DCPO, DCPI, DCPM and DCPT were mild nephrotoxicants. None of the compounds elevated serum alanine transferase activity or liver weights in the rats, however DCPT produced centrilobular necrosis. These experiments confirm that NDPS-induced nephrotoxicity is critically dependent on the presence of the succinimide ring. Furthermore, replacement of the succinimide ring with a thiazolidinedione ring produced a more pronounced effect on the liver than on the kidney. Liver damage has been reported in type II diabetic patients taking troglitazone, rosiglitazone and pioglitazone. Since these compounds also contain a thiazolidinedione ring, DCPT may be useful for investigating the role of this structural feature in hepatotoxicity.

This article describes efficient and mild protocols for preparing polysubstituted imidazoles in a single pot from aryl-substituted tosylmethyl isocyanide (TosMIC) reagents and imines generated in situ. Traditional imine-forming reactions employing virtually any aldehyde and amine followed by addition of the TosMIC reagent delivers 1,4,5-trisubstituted imidazoles with predictable regiochemistry. Employing chiral amines and aldehydes, particularly those derived from alpha-amino acids, affords imidazoles with asymmetric centers appended to N-1 or C-5 with excellent retention of chiral purity. 1,4-Disubstituted imidazoles are also readily prepared by a simple variant of the above procedure. Selecting glyoxylic acid as the aldehyde component of this procedure leads to intermediates such as 48, which readily undergo decarboxylation and elimination of the tosyl moiety to deliver 1,4-disubstituted imidazoles in high yields. Alternatively, using NH(4)OH as the amine component in conjunction with a variety of aldehydes delivers 4, 5-disubstituted imidazoles in moderate to good yields in a single pot while avoiding the need for protecting groups. Finally, the facile preparation of mono- and disubstituted oxazoles from these TosMIC reagents and aldehydes is described.

Mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates (1), obtained from the reaction of N-acyl-N-alkylglycines (2) with trifluoroacetic anhydride, react with amidines to give 5-trifluoroacetylimidazoles (3) in moderate yield. The novel ring transformations of 1 into 3 occur via an initial attack of amidines on the C-2 position of the ring.

Novel 5-ring heterocyclic building blocks are synthesized. These can be incorporated into analogs of peptide antibiotics such as microcin B17, which is a potent DNA-gyrase inhibitor that exhibits eight thiazole and oxazole moieties. In particular, the syntheses of imidazole and bisoxazole amino acids as novel peptidomimetics are reported, this includes a new procedure for the oxidative conversion of the intermediates oxazoline, imidazoline as well as oxazole-oxazoline into the corresponding heteroaromatic compounds. A mixture of 1,8-diazabicyclo-[5.4.0.]-undec-7-ene carbon tetrachloride/acetonitrile and pyridine proved to be a very effective and mild agent.

Reactive molecules susceptible to form stable acyl enzyme intermediates with D,D-peptidases and beta-lactamases were designed as potential irreversible inhibitors of Penicillin Sensitive Enzymes (PSEs). The structures examined were a series of azapeptides and oxapeptides, both analogs of the D-Ala-D-Ala substrate, and some heterocycles, such as imidazolidinones and oxazolidinones, both analogs of the beta-lactam antibiotics. The various strategies investigated for their synthesis are described and discussed. Some biological results are reported.

Novel 4-arylazole (i.e. thiazole, oxazole, and imidazole) derivatives, possessing an amino moiety at the C-5 position of the azole ring, were prepared and tested for anti-anoxic (AA) activity in mice. Among them, 5-(4-methylpiperazin-1-yl)methyl-4-(3-nitrophenyl)-2-phenylthia zole (3b, FR75094) possessed significant AA activity (10 mg/kg, i.p. and 100 mg/kg, p.o., respectively), and was also effective on anti-lipid peroxidation (ALP) assay and inhibited arachidonate-induced cerebral edema in rats. Structure-activity relationships in regard to AA activity of this series of compounds are discussed.

A variety of benzylideneoxazoles, -thiazoles, and -imidazoles derived from 2,6-di-tert-butylphenol were prepared and evaluated as dual inhibitors of 5-lipoxygenase and cyclooxygenase in rat basophilic leukemia (RBL-1) cells. The target compounds exhibit varying degrees of selectivity toward the two enzymes. Several compounds are orally active in the rat carageenan footpad edema (CFE) and mycobacterium footpad edema (MFE) antiinflammatory models. Structure-activity relationships are discussed. From this work, (Z)-5-[[3,5-bis(1,1-dimethylethyl)-4- hydroxyphenyl]-methylene]-2-imino-4-thiazolidinone methanesulfonate salt (CI-1004) was identified as a potent dual inhibitor of 5-lipoxygenase (IC50 = 0.77 microM) and cyclooxygenase (IC50 = 0.39 microM), with oral activity (ID40 = 0.6 mg/kg) in the rat MFE model of inflammation.

A series of imidazo[1,2-alpha]pyridinyl-2-oxobenzoxazolidines (4a-i), -3-oxo-2H-1,4-benzoxazines (5a-q), their thio-analogues (4j-p and 5r-t) and 5,6,7,8-tetrahydroimidazo[1,2-alpha]pyridinyl derivatives (8 and 9) were synthesized and tested for anti-stress ulcer activity in rats. Several compounds were found to be more active than the reference compounds, zolimidine, cimetidine and sucralfate. Among them, compound 4e, 5i and 5l also exhibited potent protective activity against ethanol-induced gastric lesion. The synthesis and structure-activity relationships of these compounds are discussed.

It is known that thiazolo[3,2-a][1,8]naphthyridine derivatives (3a) exhibit good antibacterial activity. Accordingly, several analogues of 3a, viz. oxazolo- and imidazolo[3,2-a][1,8]naphthyridine derivatives 3b and 3c, were synthesized and evaluated for antibacterial activity in vitro and for inhibitory activity against DNA gyrase of Escherichia coli K-12 C600. Compound 3a exhibited antibacterial activity comparable to that of ofloxacin and enoxacin against Gram-positive and Gram-negative bacteria and displayed antibacterial activity superior to that of 3b and 3c. The antibacterial activities of 3b and 3c decreased in that order. DNA gyrase inhibitory activities of 3a-c in E. coli K-12 C600 paralleled their in vitro antibacterial activity. It was found that enhancement of the DNA gyrase inhibitory activity of 3a was dependent on a certain feature of the sulfur atom of the thiazole ring.

The synthesis and in vitro antifungal activity of a novel series of cis-5-alkoxy(or acyloxy)alkyl-3-phenyl-3-(1H-imidazol-1-ylmethyl)- 2-methylisoxazolidine derivatives (6a-n) are described. The 5-[(4-chlorobenzyloxy)methyl] analogue 6h and the two 5-acyloxymethyl derivatives 6k,l demonstrated the best overall potency. Against Candida stellatoidea, the minimum inhibitory concentrations (MIC's) for 6h,k,l ranged between 0.7 and 2.0 micrograms/ml. The corresponding value for the standard drug ketoconazole was 7-20 micrograms/ml.

The synthesis and antifungal activity of a novel series of substituted 3,5-diphenyl-3-(1H-imidazol-1-ylmethyl)-2-alkylisoxazolidine derivatives (15-30) are described. The synthesis of the title compounds was accomplished via a 1,3-dipolar cycloaddition reaction of alpha-substituted ketonitrones with appropriate styrene precursors. The compounds when tested in vitro in solid agar cultures exerted a very potent antifungal activity against a wide variety of yeast and systemic mycoses and dermatophytes, especially Trichophyton and Microsporum sp., Epidermophyton floccosum and Candida stellatoidea. The in vitro activity against Aspergillus fumigatus and Candida albicans was moderate to potent. Overall, the two bis(4-chlorophenyl) analogues 18 and 19 were the most potent in vitro compounds, showing MIC values ranging between 0.2 and 7.0 microgram/mL, as compared to 0.2-20.0 micrograms/mL for ketoconazole, which was used as the positive standard in all assays. When tested in vivo in the rat vaginal candidiasis model, derivative 18, although showing significant antifungal activity when compared to controls, was less effective than ketoconazole. The title 3,5-substituted isoxazolidine compounds represent a novel class of potent antifungal agents.

A synthetic procedure for the preparation of imidazolidinediones by the base-catalyzed cyclization of propargylureas is described. This method appears to be the most versatile way of obtaining these compounds containing tertiary groups substituted on ring-nitrogen number 3. One of these derivatives, 3-tert-butyl-5,5-dimethyl-2,4-imidazolidinedione (1a), has shown a moderate level of subcutaneous metrazole seizure threshold activity (scMet indicates potential for control of petit mal epileptic seizures) in control screens on mice, as determined by the National Institute of Neurological and Communicative Disorders and Stroke.

Platinum(IV) chloride complexes with heterocyclic ligands have been prepared and characterized by infrared and electronic spectra. The compounds are of general formula Pt(L)nCl4, where L = N-ethylimidazole, N-propylimidazole, isoxazole, 3,5-dimethylisoxazole, benzoxazole, 2-methylbenzoxazole, 2,5-dimethylbenzoxazole, ethylenediamine, n = 2, 4, and also Pt(enEt2)3Cl4 X 2H2O, where enEt2 = N,N-diethylethylenediamine. These complexes are hexacoordinate with cis or trans configuration. The antitumoral activity of some complexes in mice inoculated with leukemia L1210 is reported.

A series of 1-[[[5-(substituted phenyl)-2-oxazolyl]methylene]amino]- 2,4-imidazolidinediones (6a-t) was synthesized, and the compounds were evaluated for direct skeletal muscle inhibition in the pithed rat gastrocnemius muscle preparation. The correctness of structural assignment of the new series was verified by alternate, unequivocal synthesis of one representative structure (6f). The phenyloxazoles 6d, 6g, 6j, 6k, and 6l exhibited significant skeletal muscle relaxant activity when administered intravenously and orally. The skeletal muscle relaxant effect of these five compounds is similar to that of other direct-acting skeletal muscle relaxants. The oxazole moiety proved to be an acceptable isosteric replacement for furan, as the biological activity in the oxazole series was retained. The synthesis of this new class of compounds is described, and pharmacologic evaluation data are presented. A discussion of structure-activity relationships is also presented.

The synthesis and antifungal activity of a series of novel 5-substituted 3-(2-naphthalenyl)-3-(1H-imidazol-1-ylmethyl)-2- methylisoxazolidine derivatives are described. When tested in vitro in solid agar assays, some of the compounds demonstrated moderate to potent activity against Trichophyton rubrum and Candida albicans.

The in vitro antifungal activity of a novel series of cis- and trans-5-([aryl or aryloxy (or thio)]methyl)-3-(1H-imidazol-1-ylmethyl)-3- (2-thienyl)-2-methylisoxazolidines (13-24) was evaluated and compared with ketoconazole. The title series of compounds was prepared via a 1,3-dipolar cycloaddition reaction of 1-(2-thienyl)-2-(1H-imidazol-1-yl)-N-methylethanimine N-oxides with appropriate styrenes, allyl phenyl ethers, or allyl phenyl thioether precursors. The resulting products were mixtures of the corresponding cis- and trans-diastereomers which were readily separated by flash chromatography on neutral silica gel. The majority of compounds 13-24, when tested in solid agar cultures, exhibited moderate to potent activity against Trichophyton rubrum, Aspergillus fumigatus, and Candida albicans at concentrations ranging between less than or equal to 2.0 and 70.0 micrograms/mL.

Reaction of 2,3,5,6-tetramethylphenacyl halides with formamide did not produce the expected 4(5)-(2,3,5,6-tetramethylphenyl)imidazole, but 4(5)-(2,3,5,6-tetramethylbenzoyl)imidazole (VII) was isolated as the major product together with 5-(2,3,5,6-tetramethylphenyl)oxazole (III), alpha-formylamino-2,3,5,6-tetramethylacetophenone (IV) and alpha-chloro-beta-amino-vinyl 2,3,5,6-tetramethylphenyl ketone (IX) as by-products. The corresponding mesitylene derivatives gave analogous results, whereas 4(5)-(2-methylphenyl)imidazole was obtained from 2-methylphenacyl bromide as expected according to the Bredereck's reaction. The structure of the isolated compounds were elucidated by element analysis, mass, I.R., U.V. and N.M.R. spectra, and by chemical reactivity.

The synthesis and antifungal activity of a series of novel 5-carbonyl derivatives of 3-phenyl-3-(1H-imidazol-1-ylmethyl)-2-methylisoxazolidines (4) are discussed. The preparation of the title compounds involved a 1,3-dipolar cycloaddition reaction of alpha-substituted ketonitrones with either acrylic esters, acrylamide or methyl vinyl ketone to furnish cis/trans-diastereomeric mixtures of the desired 5-carbonyl isoxazolidines 4. The anifungal activity was evaluated in vitro in solid agar cultures. Some of the compounds tested exerted moderate to potent activity against a wide variety of dermatophytes and yeast and systemic fungi.