N－芳基－2－乙基－3－羟基－4－吡啶酮的微波合成

用微波辐射从2－乙基－3－羟基－4－吡喃酮和芳胺合成了系列N－芳基－2－ 乙基－3－羟基－4－吡啶酮，并对产物进行了紫外、红外、氢核磁和质谱表征。     

Synthesis of 3-alkyl-8-substituted- and 4-hydroxy-8-substituted-2,3,4,5-tetrahydro-1H-2-benzazepines

Based on the Schmidt reaction and an iodolactone ring expansion reaction, two different synthetic routes to substituted 2,3,4,5-tetrahydro-1H-2-benzazepines were developed. The Schmidt reaction on 2,3-dihydro-2H-1-naphthalenone ( 1 ) gave 3 , the product resulting from the alkyl group migration, as the major product instead of the tetrazole 2. This prompted the investigation of the Schmidt reaction on aromatic ketones 8 and 12. The product 9 due to alkyl group migration was the major product of the Schmidt reaction on 2-methyl-3,4-dihydro-2H-1-naphthalenone ( 8 ). The β-keto diester 12 gave a mixture of decarb-oxylated lactams after the Schmidt reaction. In this case, the lactam 13 resulting from the migration of the aromatic ring dominated over the other lactam 14. When lactam 14 was subjected to nitration, a single regioisomer was produced and transformed to the bromo alcohol 19. The other approach was based on the single pot ring expansion of the iodolactone 22 to the lactam 23 in the presence of methanolic ammonia. The iodolactone 22 was readily prepared from 2-allylbenzoic acid.     

Ruthenium complexes of 3-hydroxy-4-pyranones and of 3-hydroxy-4-pyridinones

Reactions of hydrated ruthenium chloride with 2-methyl-3-hydroxy-4-pyranone, ethylmaltol (etmaltH) and with 1,2-dimethyl-3-hydroxy-4-pyridinone (dmppH) are described. The former results in the formation of Ru(etmalt)₃, but the course of the latter depends on conditions, producing the earlier-characterised Ru(dmmp)₃Cl in ethanol–water solution, Ru(dmmp)₃ in aqueous solution under mild conditions, and Ru(dmpp)₂(H₂O)₂ after extended refluxing. EXAFS studies established ruthenium-oxygen distances in Ru(etmalt)₃ and in Ru(dmmp)₃ · 6H₂O. Solubilities of Ru(dmmp)₃ in methanol–water mixtures reveal greater solubility in methanol than in water, and indications of a modest solubility maximum, and thus synergic solvation, in methanol-rich mixtures.     

2-二乙氨基-4-羟基-6-甲基嘧啶的合成

二乙基胍硝酸盐;硝酸盐;BTEA;2-二乙氨基-4-羟基-6-甲基嘧啶的合成     

Synthesis of 3-substituted-3,4-dihydro-2(1H)-pyridinones from nitriles

A number of the title compounds have been prepared through a three step reaction sequence based on the cyclization of Δ-acetal amides.     

Construction of 4-hydroxy-2-pyridinones. Total synthesis of (+)-sambutoxin

Total synthesis of (+)-sambutoxin has been achieved, establishing the relative and absolute stereochemistry of the naturally occurring mycotoxin. Efforts feature methodology for enantiocontrolled construction of 1,3-anti-dimethyl arrays and a novel Saegusa oxidation to provide a pyridinone methide leading to formation of the central dihydropyran ring.     

Asymmetric synthesis of (6R)-4-hydroxy-6-substituted-δ-lactones

A novel approach for the asymmetric synthesis of (6R)-4-hydroxy-6-substituted-δ-lactones has been achieved using asymmetric reduction of a prochiral ketone in the presence of (S)-(?)-diphenyl-prolinol/borane as a key step. The enantiomeric purity of the products was determined by chiral GC.     

Ring opening reactions of 6-oxo-substituted spiro-pyrrolidinediones: Synthesis of 4-substituted-1,5-dihydro-3-hydroxy-2-oxo-1,5-diphenyl-2H-pyrroles

Reaction of 2-oxocylalkaneglyoxylate esters with N-phenylmethyleneaniline yields spiro compounds such as 2-aza-3,4,6,-trioxo-1,2-diphenylspiro[4.4]nonane 4 and cycloalkane-2-aza-3,4,6-trioxo-1,2-diphenylspiro-[4.5]decanes 5–7 . These undergo solvolytic opening of the the oxocycloalkane ring to yield 4-substituted-1,5-dihydro-3-hydroxy-2-oxo-1,5-diphenyl-2H-pyrroles 12–17 .     

Synthesis of functionalized quinolines via Ugi and Pd-catalyzed intramolecular arylation reactions

Two types of quinoline scaffolds were constructed in a combinatorial format via the Ugi four-component reaction (U-4CR) and Pd-catalyzed intramolecular arylation reaction. The scope of this two-step synthetic sequence was examined from commercially available and synthetically accessible starting materials.     

Iron-catalyzed synthesis of functionalized 2H-chromenes via intramolecular alkyne-carbonyl metathesis

An iron-catalyzed intramolecular alkyne-aldehyde metathesis strategy of the alkynyl ether of salicylaldehyde derivatives has been developed which works under mild reaction conditions to produce the functionalized 2H-chromene derivatives. This protocol is compatible toward a wide range of functional groups, such as methoxy, fluoro, chloro, bromo, and phenyl groups. This method provides an atom-economical and environmentally friendly approach for the synthesis of a series of substituted 2H-chromenes.     

Synthesis of novel 2-substituted-5-oxycoumarans via A direct route to 2,3-dihydro-5-hydroxy-2-benzofuranacetic acids

A number of novel 2-substituted 2,3-dihydro-5-benzofuranols optionally protected on 5-OH group have been prepared via a simple two step route to racemic 2,3-dihydro-5-hydroxy-2-benzofuranacetic acids from hydroquinones and 4-bromocrotonates.     

Synthesis of 2-aryl-4-hydroxy-5-thio substituted 1,3-thiazin-6-ones via sulfenylation of 2-aryl-4-hydroxy-[1,3]thiazin-6-ones with sulfenyl chlorides

A series of 2-aryl-4-hydroxy-5-thio substituted 1,3-thiazin-6-ones were synthesized for human immunodeficiency virus-1 protease inhibition. These compounds were synthesized by the treatment of 4-hydroxy-5-thio substituted-1,3-thiazin-6-ones with the corresponding sulfenyl chlorides. The products were obtained in good isolated yields, inspite of the presence of bulkyl substitutents at the ortho position of phenyl sulfenyl chloride portion.     

Highly luminescent lanthanide complexes of 1-hydroxy-2-pyridinones

The synthesis, X-ray structure, stability, and photophysical properties of several trivalent lanthanide complexes formed from two differing bis-bidentate ligands incorporating either alkyl or alkyl ether linkages and featuring the 1-hydroxy-2-pyridinone (1,2-HOPO) chelate group in complex with Eu(III), Sm(III), and Gd(III) are reported. The Eu(III) complexes are among some of the best examples, pairing highly efficient emission (Phi tot (Eu) approximately 21.5%) with high stability (pEu approximately 18.6) in aqueous solution, and are excellent candidates for use in biological assays. A comparison of the observed behavior of the complexes with differing backbone linkages shows remarkable similarities, both in stability and photophysical properties. Low temperature photophysical measurements for a Gd(III) complex were also used to gain insight into the electronic structure and were found to agree with corresponding time-dependent density functional theory (TD-DFT) calculations for a model complex. A comparison of the high resolution Eu(III) emission spectra in solution and from single crystals also revealed a more symmetric coordination geometry about the metal ion in solution due to dynamic rotation of the observed solid state structure.     

Synthesis and characterisation of cis-dioxomolybdenum(VI) complexes of N-substituted 3-hydroxy-2-pyridinones

The butoxy- and methoxy-derivatives (HLc, and HLb, respectively) of 1-[(ethoxycarbonyl)methyl]-3-hydroxy-2-(1H)-pyridinone, HLa, were synthesized by transesterification and the mononuclear complexes [MoO2(L(a-c))2] were obtained by the reaction of the ligands with molybdenyl acetylacetonate. The three complexes were fully characterized by (1)H and (13)C NMR spectroscopy, mass spectrometry and elemental analyses. A variable temperature NMR study showed that the N-substituents do not have a significant influence on the racemisation process of the complexes. The comparison of the crystal structure of [MoO2(Lb)2] with [MoO2(La)2] confirmed that an additional methylene group does not affect the immediate coordination environment of the molybdenum centre. The methoxy-derivative HLb was also found to produce a dinuclear complex of composition [(MoO2(Lb)O)2], the structure of which was determined by X-ray diffraction.     

Synthesis of 2-carbethoxy-3-methyl-4-hydroxy-6-phenylbenzofuran derivatives

4-Hydroxybenzofuran derivatives were synthesized, and their reactions with bromine and nitric acid were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 879–882, July, 1976.     

The rearrangement of some 2-substituted-4-bromo-2,5-dinitro-6-hydroxy-3,6-dimethylcyclohex-3-en-1-ones

In chloroform at 20°, or in tetrachloroethylene at 120°, the title compounds (1) rearrange to give the α-diketone(2), the structure of which was determined by X-ray crystal structure analysis; a possible rearrangement mechanism is outlined.     

A rapid and diverse construction of 6-substituted-5,6-dihydro-4-hydroxy-2-pyrones through double Reformatsky reaction

A rapid and diverse synthesis of biologically important 6-substituted-5,6-dihydro-4-hydroxy-2-pyrones through a double Reformatsky reaction of aldehydes to δ-hydroxy-β-ketoesters followed by lactonization is described. Due to the high functional group tolerance and reaction site discrimination between aldehyde, nitrile, and ester groups in the substrate, the protocol can provide the dihydropyrones with bromo, nitro, carboxylic acid, and β-ketoester groups, which are suitable for the further derivatizations. Furthermore, the protocol has been successfully applied to the rapid total synthesis of naturally occurring Yangonin.     

Synthesis and fungicidal activity of new 4-hydroxy-6-trifluoromethyl-2-phenylindoles

Starting from 1,3-dinitro-5-trifluoromethylbenzene, a pioneering synthesis and dimethylaminomethylation of new 2-aryl- 4-hydroxy-6-trifluoromethylindoles have been performed. The study of fungicidal activity has revealed the effect of dimethylaminomethyl group position on fungitoxic properties.     

Synthesis and mechanistic study of fused 2-pyrrolines via thermolysis of 6-substituted-3,5-hexadienyl azidoformates

Thermolysis of 3,5-hexadienyl azidoformates at 300 degrees C, 0.05 Torr, led to a fused 2-pyrroline regiospecifically, regardless of the configuration E or Z between the C-3 and C-4 double bond. Thermolysis of 6-substituted-3,5(E)-hexadienyl azidoformates yielded a kinetically controlled 2-pyrroline with cis configuration between H-1 and H-8a whereas 6-substituted-3,5(Z)-hexadienyl azidoformates produced a cis and trans mixture. The mechanism was proposed as the loss of nitrogen to form an acyl nitrene, then addition to a double bond to produce an aziridine. Finally the cleavage of the C-C bond generated a vinylazomethine ylide followed by recyclization to a fused 2-pyrroline.