Reaction Of 4-methyl Research Articles

Reactions of 4-methyl- and 4,6-dimethylresorcinols with (2-ethoxyvinyl)phosphonic dichloride – synthesis of new regioisomeric cage phosphonates

Regioisomeric cage phosphonates have been prepared and isolated for the first time by the reaction of 4-methyl- and 4,6-dimethylresorcinols with (2-ethoxyvinyl)phosphonic dichloride. It has been shown that different phosphorus-containing heterocyclic compounds are formed depending on the nature of substituent at positions 4 and 6 of resorcinol aromatic ring.

Synthesis of New Derivatives Benzo[4′,5′]imidazo[2′,1′:6,1]pyrido[2,3-d]pyrimidine

The reactions of 4-methyl- and (RS)-4,6-dimethyl-2-phenyl-5,6-dihydrobenzo[4′,5′]imidazo-[2′,1′:6,1]pyrido[2,3-d]pyrimidines and 4-methyl-5,6-dihydrobenzo[4′,5′]imidazo[2′,1:6,l]pyrido[2,3-d]pyrimi-din-2-ol with aromatic and heterocyclic aldehydes under various experimental conditions were studied. It was shown that the reaction with aldehydes upon boiling in acetic anhydride involves exclusively the 6-methylene group in the a-position to the benzimidazole fragment of the tetracycle and is accompanied by a 1,3-prototropic shift, which results in the formation of 6-aryl(hetaryl)methyl-4-methyl derivatives. The 4-methyl group in the substituted 2-phenyl(hydroxy)derivatives of 5,6-dihydrobenzo[4′,5′]imidazo[2′,1′:6,1]pyrido[2,3-d]pyrimidines reacts with aldehydes only under fusion conditions in the presence of ZnCl2. The structure of the synthesized compounds was confirmed by one- and two-dimensional (NOESY) 1H NMR spectroscopy and XRD analysis.

Synthesis of 2-{[5-(aralkyl/aryl)-1,3,4-oxadiazol-2- yl]sulfanyl}-N-(4-methyl-1,3-thiazol-2-yl)acetamides: Novel bi-heterocycles as potential therapeutic agents

Purpose : To evaluate the therapeutic potential of new bi-heterocycles containing a 1,3-thiazole and 1,3,4-oxadiazole in the skeleton against Alzheimer's disease and diabetes, supported by in-silico study. Methods : The synthesis was initiated by the reaction of 4-methyl- 1,3-thiazol-2-amine (1) with bromoacetyl bromide (2) in aqueous basic medium to obtain an electrophile,2-bromo-N-(4-methyl-1,3- thiazol- 2-yl)acetamide (3). In parallel reactions, a series of carboxylic acids, 4a-r, were converted through a sequence of three steps, into respective 1,3,4-oxadiazole heterocyclic cores, 7a-r, to utilize as nucleophiles. Finally, the designed molecules, 8a-r, were synthesized by coupling 7a-r individually with 3 in an aprotic polar solvent. The structures of these bi-heterocycles were elucidated by infrared (IR), electron ionization-mass spectrometry (EI-MS), proton nuclear magnetic resonance (1H-NMR) and carbon nuclear magnetic resonance ( 13 C-NMR). To evaluate their enzyme inhibitory potential, 8a-r were screened against acetylcholinesterase (AChE), but brine shrimp lethality bioassay. Results: The most active compound against AChE was 8l with half-maximal inhibitory concentration (IC 50 ) of 17.25 ± 0.07 μM. Against BChE, the highest inhibitory effect was shown by 8k (56.23 ± 0.09 μM). Compound 8f (161.26 ± 0.23μM) was recognized as a fairly good inhibitor of urease. In view of its inhibition of α-glucosidase, 8o (57.35 ± 0.17μM) was considered a potential therapeutic agent. Conclusion: The results indicate that some of the synthesized products with low toxicity exhibit notable enzyme inhibitory activity against selected enzymes compared with the reference drug, and therefore, are of potential therapeutic interest Keywords: 4-Methyl-1,3-thiazol-2-amine,1,3,4-Oxadiazole, Cholinesterases, α-Glucosidase, Urease, Brine shrimp

Synthesis, spectroscopic characterization and crystallographic behavior of ethyl 2-(4-methyl-(2-benzylidenehydrazinyl))thiazole-4-carboxylate: Experimental and theoretical (DFT) studies

The ethyl 2-(4-methyl-(2-benzylidenehydrazinyl))thiazole-4-carboxylate (1) was synthesized via reaction of 4-methyl-(1-benzylidenehydrazinyl)-2-carbothioamide with ethyl bromopyruvate. The compound is characterized by FTIR and NMR before being analyzed by X-ray diffraction method. These properties of the structure are further investigated by DFT quantum chemical methods. The molecular geometry of the compound (1) was optimized using density functional theory (DFT/B3LYP) method with the cc-pVTZ basis sets in ground state. The MEP map exhibits the negative potential sites are on electronegative atoms and the positive potential sites around the hydrogen atoms. The MEP and Mulliken population analysis confirm the hydrogen bonding sites in the molecule. We have also calculated geometric parameters (bond lengths, bond angles, torsion angles), vibrational assignments and chemical shifts of the compound (1) theoretically and compared with the experimental data, these values are found in good agreement with each other. Although theoretical calculations were carried out in gas phase, however no significant differences were found in these values.

Proton-Transfer Reaction of 4-Methyl 2,6-Diformyl Phenol in Cyclodextrin Nanocage

We report here on the steady-state and time-resolved fluorescence studies on proton-transfer (PT) reaction of 4-methyl 2,6-diformyl phenol (MFOH) in confined nanocavities in three solvents, dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), and water. Though DMSO and DMF individually interact with MFOH in a similar fashion, their modes of interaction get significantly modified in the presence of cyclodextrin (CD) nanocages. In DMSO, in the ground state, the solvated molecular anion of MFOH forms 1:1 inclusion complex with beta- or gamma-CD and attains greater stability compared to the normal form. In DMF, the solvated molecular anion gets converted to the H-bonded complex within the CD cavity resulting in a 50-nm blue shift in the absorption spectra. In the excited state, the anionic species gets more stabilized in DMSO while in DMF it is significantly destabilized in the presence of CDs. However, in case of water, MFOH gets trapped inside the water cages so that the CDs fail to complex with it effectively. There are also no changes in the excited-state lifetimes in water in the presence of CDs, but in case of DMSO and DMF, because of restricted rotation of the formyl group within the CD cavity, the contribution of the shorter lifetime components reduce significantly increasing the larger components. Some theoretical calculations at the AM1 level of approximation have also been carried out to demonstrate how the dipolar nature of the solvent influences excited-state PT in confined media.

Synthesis and Antimicrobial Activity of Some Annelated Quinazoline Derivatives

A highly efficient and versatile synthetic approach to the synthesis of annelated quinazoline derivatives viz [1,2,4]triazino[4,3- c]quinazoline 5–7, [1,3,5]triazino[1,2- c]quinazoline 11, thiazolidinylquinazoline 9, quinazolino[4,3- b] quinazolin-8-one 12 and imidazoquinazolines 14a,b,15. Also, a variety of pyrazolylquinazolines 19–21, pyrimidinylquinazolines 22a,b were obtained via a sequence of heterocyclisation reactions of 4-methyl- N-[4-(4-oxo-3,4-dihydroquinazolin-2-yl)phenyl]benzenesulfonamide (2) with different reagents. The new compounds were synthesised with the objective of studying their antimicrobial activity.

Reaction of 4-methyl, 4-phenyl, and 4-hydrogen substituted 1-lithio-1,3-butadienes with aldehydes: preparation of multiply substituted cyclopentadienes

Abstract Reaction of aldehydes with 1-lithio-1,3-butadiene reagents possessing a methyl substituent, a phenyl substituent or a hydrogen at position 4 of the butadienyl skeletons was studied. Polysubstituted cyclopentadiene derivatives were obtained in high yields upon hydrolysis using strong acidic solution. Reaction mechanism study revealed that these cyclopentadienes were formed via an acid-promoted cyclization of conjugated dienols. Thus, stereodefined all-cis substituted dienols or a wide diversity of substituted cyclopentadienes can be obtained from the same 1-lithio-1,3-butadiene reagent and aldehyde by adjusting the hydrolysis conditions.

Primary and secondary H/D isotope effects in the addition of triazolinedione to 2,5-dimethyl-2,4-hexadiene. Mechanistic insights into the reaction pathways

Primary and secondary isotope effects were determined for the reaction of 4-methyl[1,2,4]triazoline-3,5-dione with 2,5-dimethyl-2,4-hexadiene-1,1,1,2',2',2'-d6. The results are consistent with the formation of an aziridinium imide intermediate in equilibrium with an open zwitterion. At higher temperatures, the aziridinium imide prevails and can be either transformed to the ene adduct in a slow step, or trapped by the solvent if the reaction is carried out in methanol. At lower temperatures, the entropically favored open zwitterion is formed preferentially, that either polymerizes in chloroform or can be trapped by methanol.

Synthesis and immunotropic properties of 5-substituted 1,5-benzodiazepin-2-ones derivatives in cultures of human peripheral blood cells, Part III.

The reaction of 4-methyl-(A) and 3-methyl-1H-2,3,4,5-tetrahydro-1,5-benzodiazepin-2-one (B) with selected alpha,beta-unsaturated acid chlorides: crotonoyl, cinnamoyl, and 4-nitrocinnamoyl is described. We have also characterized immunotropic activities of these compounds in the proliferative response of human lymphocytes to phytohemagglutinin A (PHA) or to allogeneic cells in one-way mixed lymphocyte reaction (MLR), as well as their action on tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) production in peripheral blood mononuclear cells (PBMC) and mixed lymphocyte cultures (MLC). Some of the compounds exhibited regulatory activities in the proliferative response of cells to PHA depending on the reactivity of cells to PHA. The MLR induced proliferation of lymphocytes was moderately inhibited by two selected compounds. The compounds showed also inhibitor properties with regard to lipopolysaccharide (LPS)- and MLR-induced TNF-alpha production. Structure-activity relationship was discussed.

Reactions of 4-methyl- o-benzoquinone, generated chemically or enzymatically, in the presence of l-proline

The reactions of 4-methyl- o-benzoquinone in the presence of l-proline were studied by rapid scanning spectrophotometry. It was concluded that it was transformed into 5-methyl-4- N-propyl- o-benzoquinone, according to the equation: 2(4-methyl- o-benzoquinone) + l-proline → 4-methylcatechol + 5-methyl-4- N-prolyl- o-benzoquinone. Rate constants for the reaction of 4-methyl- o-benzoquinone with water and l-proline have been measured.

ChemInform Abstract: NOVEL REACTION OF 4‐METHYL‐ AND 4‐TERT‐BUTYLPHENOLS WITH TETRASULFUR TETRANITRIDE AFFORDING 2,1,3‐BENZOTHIADIAZOLES

Chemischer InformationsdienstVolume 15, Issue 8 Heterocyclic Compounds ChemInform Abstract: NOVEL REACTION OF 4-METHYL- AND 4-TERT-BUTYLPHENOLS WITH TETRASULFUR TETRANITRIDE AFFORDING 2,1,3-BENZOTHIADIAZOLES S. MATAKA, S. MATAKASearch for more papers by this authorK. TAKAHASHI, K. TAKAHASHISearch for more papers by this authorS. SHIWAKU, S. SHIWAKUSearch for more papers by this authorM. TASHIRO, M. TASHIROSearch for more papers by this author S. MATAKA, S. MATAKASearch for more papers by this authorK. TAKAHASHI, K. TAKAHASHISearch for more papers by this authorS. SHIWAKU, S. SHIWAKUSearch for more papers by this authorM. TASHIRO, M. TASHIROSearch for more papers by this author First published: February 21, 1984 https://doi.org/10.1002/chin.198408179AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume15, Issue8February 21, 1984 RelatedInformation

Novel reaction of 4-methyl- and 4-t-butyl-phenols with tetrasulphur tetranitride affording 2,1,3-benzothiadiazoles

Reaction of tetrasulphur tetranitride (N4S4) with 4-methyl-(1a, b) and 4-t-butyl-phenols (1c–j) gave the 2,1,3-benzothiadiazoles (2a–e).

Reactions of 4-methyl(chloro)sulfonyl-2,3,5,6-tetrabromopyridines with nucleophilic reagents

The MeSO2 group is replaced in the reaction of 4-methylsulfonyltetrabromopyridine with small nucleophiles, whereas the Br atom in the 2 position is replaced in the reaction with bulky nucleophiles. Depending on the temperature conditions and the ratio of the reacting substances, 4-chlorosulfonyltetrabromopyridine reacts with primary amines to give either the corresponding amides or amines. It was established that the corresponding amines are formed when tetrabromopyridinesulfonic acid ω-hydroxyalkylamides are heated with triethylamine.

Quinol Imide Acetates. V. The Preparation and Reactions of 4-Methyl- and 4-Phenyl-p-quinolbenzenesulfonimide Acetates

Quinol Imide Acetates. V. The Preparation and Reactions of 4-Methyl- and 4-Phenyl-p-quinolbenzenesulfonimide Acetates