Laser photolysis of 1-(4-nitrophenyl)-3-methylpyrazole and 1-ethyl-3-(4-nitrophenyl)-5-chloropyrazole

The spectral kinetic characteristics of the triplet states of 1-(4-nitrophenyl)-3-methylpyrazole (1) and 1-ethyl-3-(4-nitrophenyl)-5-chloropyrazole (2) were studied by the laser nanosecond photolysis technique in different solvents. The triplet lifetimes (τ_T) of molecules 1 and 2 were found to depend strongly on the solvent nature. An increase in τ_T by approximately two orders of magnitude on going from nonpolar and polar aprotic solvents (τ_T ≤ 15 ns) to aqueous-acetonitrile solutions (τ_T = 1100 ns for a volume acetonitrile to water ratio of 1 : 3) was analyzed, taking into account the influence of the medium on the relative contribution of the n,π*- and π,π*-configurations to the lowest triplet state. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1115–1119, May, 2005.     

Revealing and comparing different excited-state intramolecular proton transfer processes for 3-(4-dimethylamino-phenyl)-1-(4-fluoro-2-hydroxy-phenyl)-propenone and 3-(4-dimethylamino-phenyl)-1-(4-fluoro-2-hydroxy-phenyl)-3-hydroxy-propenon

Two novel 2′-hydroxychalcone derivatives (i.e., M1 and M2) are explored in this work. We mainly focus on investigating the effects of photoexcitation on hydrogen bonds and on the excited-state intramolecular proton transfer (ESIPT) process. On the basis of calculations of electrostatic potential surface and intramolecular interactions, we verify the formation of hydrogen bond O1 H2···O3 in both S₀ and S₁ states. Exploring the ultraviolet–visible spectra in the liquid phase, our simulated results reappear in the experimental phenomenon. Analyzing molecular geometry and infrared stretching vibrational spectra, we confirm O1 H2···O3 is strengthened for both M1 and M2 in the S₁ state. We further confirm that charge redistribution facilitates ESIPT tendency. Constructing potential energy curves, we find the ultrafast ESIPT behavior for M1, which is because of the deficiency of side hydroxyl moiety comparing with M2. This work makes a reasonable affiliation of the ESIPT mechanism for M1 and M2. We wish this paper could facilitate understanding these two novel systems and promote their applications.     

Synthesis of 1-(3',4'-dihydroxyphenyl)-7-(4"-hydroxyphenyl)- 4hepten-3-one

Natural diarylheptanoids have significant bioactivities. Some of them are potent inhibitors against prostaglandin biosynthesizing enzyme (PG synthetase) and 5-lipoxygenase (LT synthetase)1-2. Compound 1 was firstly isolated from Alnus rubra bark3. So far its synthesis has not been reported yet. Herein, we report the synthesis of compound 1. Meantime, compound 24 was also obtianed as an intermediate. Compound 7 and 16 were converted to compound 10 and 18 respectively, because compound 1…     

Molecular and Crystal Structure of 1-(4-Chlorophenyl)- 3- (4-Nitrophenyl)- 1-Triazene

１　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｈａｓｂｅｅｎｒｅｐｏｒｔｅｄｔｈａｔ１,３－ｄｉｐｈｅｎｙｌｔｒｉａｚｅｎｅｓｈｏｗｓａｕｔｉｔｕｍｏｒａｃｔｉｖｉｔｙｃｏｍｐａ－ｒａｂｌｅｔｏｔｈａｔｏｆ３,３－ｄｉｍｅｔｈｙｌ－１－ｄｉａｒｙｌｔｒｉａｚｅｎｅｓ．１,３－ｄｉａｒｙｌｔｒｉａｚｅｎｅｓｃａｎａｃｔａｓｐｒｏ－ｄｒｕｇｓ,ｏｒｃａｒｒｉｅｒｏｆｄｉａｚｏｎｉｕｍｃｏｍｐｏｕｎｄｓ,ｓｉｎｃｅｔｈｅｙｕｎｄｅｒｇｏｈｙｄｒｏｌｙｓｉｓｔｏｆｏｒｍａｒｙｌｄｉａｚｏｎｉｕｍｃｏｍｐｏｕｎｄｓ〔１…     

Diels-alder reaction of (E)-4-(2-nitroethenyl)-1H-imidazoles and methyl (E)-3-(1-imidazol-4-yl)propenoates

Diels-Alder reaction of methyl (E)-3-(1H-imidazol-4-yl)propenoates 2, 3a-c and (E)4-(2-nitroethenyl)-1H-imidazoles 3d,e with 2,3-dimethyl-1,3-butadiene, cyclopentadiene, and cyclohexa-1,3-diene gave the corresponding cycloadducts 6–9 .     

The crystal structure of 1-(4-chlorophenyl)-3-(4-methylbenzoyl)thiourea

1-(4-Chlorophenyl)-3-(4-methylbenzoyl)thiourea was synthesized and characterized by IR,¹H and ¹³C NMR, mass spectroscopy and the elemental analysis. The crystal structure was confirmed from single crystal X-ray diffraction data. It crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a=12.038(3), b=6.330(6), c=18.912(5) Å and β=100.32(3)°. There is a strong intramolecular hydrogen bond of the type N?H...O, with distance N1...O1=2.659(3) Å. The structure is composed of dimers related by inversion centers. The dimers are formed by intermolecular interactions of the type N?H...S with N...S separation of 3.440(2) Å. The mass fragmentation pattern has also been discussed.     

Synthesis of some new pyrazolyl-thiazolidinone derivatives starting from 1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazole-4-carboxaldehyde

Russian Journal of General Chemistry - A novel synthetic approach to (E)-1-{[1-(3-chlorophenyl)-3-[(4-methoxyphenyl-1H-pyrazol-4-yl)- methylene]hydrazono}-3-phenylthiazolidin-4-one starting from...     

Synthesis of 1-(4-butoxyphenyl)-1-cyclohexyl-3-(4-arylpiperazin-1-yl)-2-phenylpropan-1-ols and their dihydrochlorides

Aminomethylation of 1-(4-butoxyphenyl)-2-phenylethanone with paraformaldehyde and substituted piperazines in ethanol medium results in 1-(4-butoxyphenyl)-3-(4-R-piperazin-1-yl)-2-phenylpropan-1-ones. The latter react with cyclohexylmagnesium halide to give 1-(4-butoxyphenyl)-1-cyclohexyl-3-(4-arylpiperazin-1-yl)-2-phenylpropan-1-ols. Reduction of the prepared β-aminoketones with lithium aluminum hydride in absolute diethyl ether leads to the secondary aminopropanols. The prepared compounds could be converted into the corresponding dihydrochlorides.     

Synthesis and Crystal Structure of 2（1-Phenyl-3-methyl-5-chloro-1H-pyrazol-4-yl）-3-（1-naphthoylamido）-4-thiazolidinone

1INTRODUCTIONManypyrazolederivativeshavebeenreportedtoshowvariousbiologicalactivitiestobeusedasbactericide[1],fungicide[2],herbicide[3],insecticide[4]andvirucide[5]agents.Inaddition,4-thiazolidinoneplaysavitalroleowingtoitswiderangeofbiologi-calactivities…     

5-(1-Alkenyl)-1, 3, 4-oxadiazol-2(3H)-one

3-(2-alkenoyl)-thiocarbazic acid O-methyl esters 1 are desulfurated by bromine and the unknown intermediates are transformed by alkali to 5-(1-alkenyl)-1, 3, 4-oxadiazol-2(3H)-ones ( 2 ). This type of oxadiazolone substitution is not realizable by the common ring closure of hydrazides with phosgene due to pyrazolidinone ring closure of unsaturated acids with hydrazine.     

2-(1-苯基/取代苯基-3-甲基-5-氯-1H-4-吡唑基)-3-芳酰胺-4-噻唑啉酮的合成及生物活性

利用1-芳基-3-甲基-5-氯-1H-4-吡唑醛(2)分别与取代苯甲酰肼反应, 进一步与巯基乙酸关环, 合成了11个新的2-(1-芳基-3-甲基-5-氯-1H-4-吡唑基)-3-芳酰胺-4-噻唑啉酮类化合物 3a～3k, 并利用元素分析, IR, ¹H NMR和X-ray晶体衍射确定了其结构. 初步生物活性表明: 3e具有杀菌活性, 3e和3k具有除草活性.     

Molecular and Crystal Structure of 1-(4-Chlorophenyl)-3-(2-nitrophenyl)-1-triazene

1　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｈａｓｂｅｅｎｒｅｐｏｒｔｅｄｔｈａｔ1,3ｄｉｐｈｅｎｙｌｔｒｉａｚｅｎｅｓｈｏｗｓａｎｔｉｔｕｍｏｕｒａｃｔｉｖｉｔｙｃｏｍｐａｒａｂｌｅｔｏｔｈａｔｏｆ3,3ｄｉｍｅｔｈｙｌ1ａｒｙｌｔｒｉａｚｅｎｅｓ.1,3Ｄｉａｒｙｌｔｒｉａｚｅｎｅｓｃａｎａｃｔａｓｐｒｏｄｒｕｇｓ,ｏｒ‘ｃａｒｒｉｅｒｓ’ｏｆｄｉａｚｏｎｉｕｍｃｏｍｐｏｕｎｄｓ,ｓｉｎｃｅｔｈｅｙｕｎｄｅｒｇｏｈｙｄｒｏｌｙｓｉｓｔｏｆｏｒｍａｒｙｌｄｉａｚｏｎｉｕｍｃｏｍｐｏｕｎｄｓ[1,2].Ａｎｄｓｏｍｅｏｎｅｈ…     

Synthesis of Gingerenone C and 5-Hydroxy-1-(4'-hydroxy- 3'-methoxyphenyl)-7-(4"-hydroxyphenyl)-3-heptanone

The two diarylheptanoids (E)-1-(4'-hydroxy-3'-methoxyphenyl)-7-(4"-hydroxyphenyl) hept-4-en-3-one 1 (Gingerenone C) and (±)-5-hydroxy-1-(4'-hydroxy-3'-methoxyphenyl)-7-(4"-hydroxyphenyl)-3-heptanone 2 were synthesized from vanillin 3 and 4-hydroxybenzaldehyde 9.     

Synthesis and Antimicrobial Activity of 3-(1-Aryl-1H-1,2,3-triazol-4-yl)-2-(4-fluorophenyl)-1-(2-hydroxy-4-methoxyphenyl)propan-1-ones

Russian Journal of General Chemistry - A number of novel 3-(1-aryl-1H-1,2,3-triazol-4-yl)-2-(4-fluorophenyl)-1-(2-hydroxy-4-methoxyphenyl) propan-1-ones has been synthesized from...     

Synthesis and Crystal Structure of 2-（4-Fluoro-2-（4-fluorophenoxy）phenyl）-1-（1H- 1,2,4-triazol-1-ylmethyl）-3-methoxy-isopropy Alcohol

The title compound 2-（4-fluoro-2-（4-fluorophenoxy）phenyl）-1-（1H-1,2,4-triazol- 1-ylmethyl）-3-methoxy-isopropy alcohol has been synthesized by the treatment of 1-[2-（4-fluoro- 2-（4-fluorophenoxy）phenyl）-2,3-epoxypropyl]-1H-1,2,4-triazole with sodium methoxide. It belongs to orthorhombic, space group P212121, with a = 9.7229（19）, b = 11.516（2）, c = 16.047（3）A, C18H17F2 N3O3, Mr = 361.35, V = 1796.7（6）A^3, Z = 4, Dc = 1.3359 g/cm^3, F（000） = 752, p = 0.106 mm^-1, the final R = 0.0329 and wR = 0.0803 for 1821 unique reflections. The dihedral angles made by the triazole ring with two benzene rings are 43.56（3） and 54.78（2）°, respectively. The intermolecular hydrogen bond in the crystal lattice plays an important role in stabilizing the structure.     

Preparation and Structure of (E)-1-(3′-Hydroxy-2-Furanyl)-3-(3″-Hydroxy-4″-Methoxyphenyl)-2-Propen-1-One

Abstract

A facile procedure is presented for the synthesis of (E)-1-(3′-hydroxy-2′-furanyl)-3-(3″-hydroxy-4″-methoxyphenyl)-2- propen-1-one (6). Galactosylisomaltol (1) was condensed with isovanillin (2) under strong alkaline conditions at 25 [ddot]C to form (E)-1-(3′-O-β-D-galactopyranosyloxy-2′-furanyl)-3-(3″- hydroxy-4″-methoxyphenyl)-2-propen-1-one (4). (E)-1-(3′-hydroxy-2′-furanyl)-3-(3″-hydroxy-4″-methoxyphenyl)-2-propen-1-one (6) was obtained by acid hydrolysis of 4 in a 53.9% yield. This hetero-cyclic 2-propen-1-one was characterized on the basis of spectral data (IR and ¹H NMR), physicochemical properties, and conversion to a mono-O-acetyl derivative.     

Lithiation of 2-Alkyl-3-amino- and 2-Alkyl-3-(methylamino)-4(3H)-quinazolinones(1)

3-Amino-2-methyl-4(3H)-quinazolinone has been doubly lithiated, on nitrogen and in the 2-methyl group, with n-butyllithium. The lithium reagent thus obtained reacts with a variety of electrophiles (D(2)O, benzophenone, cyclohexanone, cyclopentanone, acetophenone, benzaldehyde, tetraisopropylthiuram disulfide (TITD)) to give the corresponding 2-substituted derivatives in very good yields. Reactions of the dilithio reagent with 2 molar equiv of methyl iodide or phenyl isocyanate give disubstituted derivatives. Double lithiation of the 2-ethyl and 2-propyl analogues have been achieved using LDA, and subsequent reactions with most electophiles are then similar. In the reaction of the dianion of the 2-ethyl compound with TITD, deamination from position 3 takes place with the formation of the 2-substituted derivative. In reactions with prochiral ketones, the dianion of the 2-ethyl compound gives very high diastereoselectivity. Lithiation and subsequent reactions of 3-(methylamino) analogues take place in a similar manner, thus providing access to a range of substituted 3-(methylamino)-2-alkyl-4(3H)-quinazolinones by a general procedure. Lithiation of 3-(dimethylamino)-2-ethyl-4(3H)-quinazolinone did not take place under similar conditions. Lithiation of 3-amino-2-unsubstituted-4(3H)-quinazolinone was also unsuccessful.     

Synthesis and Crystal Structure of 2-(4-Fluoro-2-(4-fluorophenoxy) phenyl)-1-(1H-1,2,4-triazol-l-ylmethyl)-3-methoxy-isopropy Alcohol

The title compound 2-(4-fluoro-2-(4-fluorophenoxy)phenyl)-1-(1H-1,2,4-triazol-z 1-ylmethyl)-3-methoxy-isopropy alcohol has been synthesized by the treatment of 1-[2-(4-fluoro-2-(4-fluorophenoxy)phenyl)-2,3-epoxypropyl]-1H-1,2,4-tdazole with sodium methoxide. It be-longs to orthorhombic, space group P212121, with a=9.7229(19), b=11.516(2), c=16.047(3) A, C18H17F2N3O3, Mr-361.35, V=1796.7(6) A3, Z=4, Dc=1.3359 g/cm3, F(000)=752,μ=0.106 mm-1, the final R=0.0329 and wR=0.0803 for 1821 unique reflections. The dihedral angles made by the triazole ring with two benzene rings are 43.56(3) and 54.78(2)°, respectively. The intermolecular hydrogen bond in the crystal lattice plays an important role in stabilizing the structure.     

Synthese von (±)-(E)-2-(1-thia-4-äthoxycarbonylbutyl)-4-(3-hydroxy-1-octenyl)-Δ1-pyrrolin und seiner analogen

Starting from 4-methoxycarbonylpyrrolidin-2-one (1) the racemic thiolactim ethers (7a-h) can be obtained via S-alkylation of the thiolactam alcohol (3), subsequent oxidation, Horner-Emmons-Wittig reaction and reduction of the enones.     

Synthesis and Crystal Structure of Rctt-1-(2-benzoxazolyl)-2-(4-chlorophenyl)-4-phenyl-3-(4-pyridinyl)cyclobutane

1INTRODUCTIONThephotodimerizationof1,2-bisarylethenederivativesisaconvenientwayforsynthesizingtetraarylsubstitutedcyclobutane.Forthisreason,thephotochemistryofstilbeneandstyrylpyridinederivativeshasbeenextensivelystudied[1,2].UpontheirradiationwithUVlight(?=300～400nm),thesemonomersareconvertedtohead-to-tailphotodimersinpolarsolventwithperfectyields.Inrecentyears,ourgrouphasbeenstudyingthephotodimerizationreactionsofheteroarylethenescontainingbenzoxazolyl[3]andphenyloxazolyl[4]groups.Itw…