The solid-state michael addition of indole to 4-arylidene-3-methyl-5-pyrazolone

The Michael addition reactions of indole to 4-arylidene-3-methyl-1-phenyl-5-pyrazolone 1 were investigated in the solid state, by which a series of new compounds, 1-aryl-1-(3-indolyl)-1-(3′-methyl-1′-phenyl-5′-pyrazolon-4′-yl)methanes 2 , were easily obtained. This provides a feasible method of preparing novel compounds containing two heterocyclic groups at the same carbon.     

Synthesis and cytotoxicity of phenyl-vinyl derivatives of 4,6,6-trimethyl-2-oxo-1,2,5,6-tetrahydropyridine-3-carbonitrile

A series of phenylvinyl derivatives of 4,6,6-trimethyl-2-oxo-1,2,5,6-tetrahydropyridine-3-carbonitriles has been synthesized and their cytotoxic activity towards HT-1080 (human fibrosarcoma) and MG 22A (mouse hepatoma) tumor cells studied. It was found that the 2-nitro-, 2- and 3-chloro, 2-fluoro, and 2-bromophenyl derivatives showed high cytotoxic activity towards both cell lines. The toxicity towards NIH 3T3 normal mouse embryonic fibroblasts depends on the nature and position of the substituent in the phenyl ring. The greatest selectivity of cytotoxic effect was seen in the 2-bromophenyl derivative.     

The solid-state michael addition of 3-methyl-1-phenyl-5-pyrazolone

A novel solid-state Michael addition between pyrazolone 1 and 4-arylidenepyrazolones 2 at ambient temperature produced Michael adducts, 4,4′-arylidenebis(3-methyl-1-phenyl-5-pyrazolones) 3. Pyrazolones 3 formed salts 4 with Cu²⁺ in solution, indicating the enolic structure of the pyrazolone rings. The reactivity of 2 with 1 is discussed in terms of the electronic and steric effects of the substituent on the arylidene group of compounds 2 . Pyrazolone 1 also underwent the solid state Michael addition reaction with maleimide at 100° to give the adducts 7,8 and 9 .     

Molecular and crystal structure of 4,6,6-trimethyl-2-oxo-5,6-dihydro-2H-pyran-3-carbonitrile and 4,6,6-trimethyl-2-oxo-1,2,5,6-tetrahydropyridine-3-carbonitrile

Single crystals of 4,6,6-trimethyl-2-oxo-5,6-dihydro-2H-pyran-3-carbonitrile and 4,6,6-trimethyl-2-oxo-1,2,5,6-tetrahydropyridine-3-carbonitrile were prepared and submitted to X-ray diffraction analysis. Both compounds have a molecular structure belonging to the C₁ symmetry group. The heterocyclic rings are in a distorted envelope conformation. The crystals belong to the monoclinic system and each contain four molecules in the unit cell. In the crystal the pyridine derivative exists in the form of centrosymmetric dimers stabilized by intermolecular hydrogen bonds between the oxygen atoms of the carbonyl group and the hydrogen atom at the nitrogen atom of the ring. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1620–1624, November, 2007.     

Novel michael addition networks containing urethane hydrogen bonding

Covalently crosslinked networks based on poly(propylene glycol) bis(acetoacetate) with either neopentyl glycol diacrylate or hydroxyethyl acrylate derivatized bis(4‐isocyanatocyclohexyl)methane (HMDI) were prepared utilizing the Michael addition reaction in the presence of catalytic quantities of diazabicyclo[5.4.0]undec‐7‐ene (DBU). These networks were prepared in the absence of solvent at 23 °C without the formation of byproducts. Mechanical and thermal analyses of the networks were performed utilizing DMA, tensile testing, and TGA. Tensile analysis revealed that the introduction of hydrogen‐bonding urethane linkages in the diacrylate segment resulted in higher tensile strengths and elongation to break compared with nonhydrogen‐bonding analogs. All crosslinked products exhibited high gel fractions and excellent thermomechanical properties. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4118–4128, 2007     

Quantum-chemical investigation of the mechanism of trans-cis photoisomerization of 4-[2-(2-chlorophenyl)vinyl]-6,6-dimethyl-2-oxo-1,2,5,6-tetrahydropyridine-3-carbonitrile

A quantum-chemical investigation has been carried out by the semiempirical AM1 method of the trans-cis photoisomerization mechanism of 4-[2-(2-chlorophenyl)vinyl]-6,6-dimethyl-2-oxo-1,2,5,6-tetra- hydropyridine-3-carbonitrile. It was shown that the isomerization process proceeds in the excited singlet state S₁ by rotation of the 2-chlorophenyl substituent around the C(2)–C(3) bond. Electronic absorption spectra of the isomers were calculated by the INDO/S method Transitions caused by exitation of an electron from HOMO to LUMO were characterized by the greatest intensity.     

Synthesis of Some Novel Biologically Active Disperse Dyes Derived from 4-Methyl-2,6-dioxo-1-propyl-1,2,5,6-tetrahydro-pyridine-3-carbonitrile as Coupling Component and Their Colour Assessment on Polyester Fabrics

A series of novel azo-disperse dyes containing alkylhydrazonopyridinone structures were synthesized. 4-Methyl-2,6-dioxo-1-propyl-1,2,5,6-tetrahydropyridine-3-carbonitrile (8) is synthesized by one-pot synthesis using ethyl cyanoacetate, propylamine, and ethyl acetoacetate. Compound 8 is then coupled with aromatic and heteroaromatic diazonium salts to afford the corresponding aryl- and heteroaryl-4-methyl-2,6-dioxo-1-propyl-1,2,5,6-tetrahydropyridine-3-carbonitriles 12a,b and 13a-c. Structural assignments to the dyes were made using NMR spectroscopic methods. A high temperature dyeing method was employed to apply these dyes to polyester fabrics. Most of the dyed fabrics tested displayed very good light fastness levels and good wash fastness. Finally, the biological activity of the prepared dyes against Gram positive bacteria and Gram negative bacteria were evaluated.     

Double michael addition reactions to tetrakis sulfonyl activated olefins

A new class of bis Michael adducts are prepared from 1,3‐bis‐[2‐(2‐arylethenesulfonyl)‐vinyl]‐benzenes and 1,4‐bis‐[2‐(2‐arylethenesulfonyl)‐vinyl]‐benzenes by double Michael addition reaction with active methylene compounds.     

Asymmetric intramolecular michael addition of alpha-sulfinyl vinylic carbanion to enoates

The first example of an asymmetric intramolecular Michael addition reaction with use of alpha-lithiated vinylic sulfoxide as a Michael donor is reported. Michael addition of the alpha-lithiated vinylic sulfoxide to (Z)-enoates proceeds with high diastereoselectivity to give the adducts with (R)-configuration at the beta-position of the ester in the five-membered-ring formation. The selectivity was reversed in the six-membered-ring formation. The resulting ester enolates were reacted with alkyl halides or benzaldehyde with high diastereoselectivity.     

Organocatalytic asymmetric michael addition of aldehydes to beta-nitroacroleine dimethyl acetal

[Structure: see text] The organocatalytic asymmetric Michael addition of aldehydes to beta-nitroacroleine dimethyl acetal has been studied in detail. The reaction took place with excellent yields and high stereoselectivities when a chiral beta-amino alcohol such as L-prolinol was employed as the catalyst, leaving a formation of highly functionalized enantioenriched compounds containing two differentiated formyl groups together with a nitro moiety.     

A study on the michael addition of dialkylphosphites to methylvinylketone

The addition of dialkylphosphites to methylvinylketone giving dialkyl‐3‐oxobutylphos‐ phonates was studied applying different reagents, such as NaOR/ROH, NaOH/H₂O under PTC, DBU, and R₃Al (R = Me, Et) under different conditions to find the optimum choice regarding efficiency and selectivity. Possible extensions to a few other model compounds were also investigated. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:226–229, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20266