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1.
Julio Belmar Fredy R. Prez Yanko Moreno Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o705-o708
The first two crystal structures of enamines derived from 1‐n‐alkyl‐3‐methyl‐5‐pyrazolones, namely 1‐(n‐hexyl)‐3‐methyl‐4‐[1‐(phenylamino)propylidene]‐2‐pyrazolin‐5‐one, C19H27N3O, (I), and N,N′‐bis{1‐[1‐(n‐hexyl)‐3‐methyl‐5‐oxo‐2‐pyrazolin‐4‐ylidene]ethyl}hexane‐1,6‐diamine, C30H52N6O2, (II), are reported. The molecule of (II) lies about an inversion centre. Both (I) and (II) are stabilized by intramolecular N—H⋯O hydrogen bonding. This confirms previous results based on spectroscopic evidence alone. 相似文献
2.
The Reformatskii reagent obtained from 3-bromotetrahydrofuran-2-one reacts with alkyl esters of 6-bromo- and 6,8-dibromo-2-oxochromene-3-carboxylic acid or alkyl esters and N-benzylamide of 3-oxo-3H-benzo[f]chromene-2-carboxylic acid to form alkyl esters of 6-bromo- and 6,8-dibromo-2-oxo-4-(2-oxotetrahydrofuran-3-yl)chroman-3-carboxylic acid or alkyl esters and N-benzylamide of 2,3- dihydro-3-oxo-1-(2-oxotetrahdrofuran-3-yl)-1H-benzo[f]chromene-2-carboxylic acid as a mixture of two diastereomers.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 9, 2004, pp. 1513–1515.Original Russian Text Copyright © 2004 by Shchepin, Fotin, Shurov.This revised version was published online in April 2005 with a corrected cover date. 相似文献
3.
Yoshihisa Kurasawa Akiko Tsuruoka Nanae Rikiishi Noriko Fujiwara Yoshihisa Okamoto Ho Sik Kim 《Journal of heterocyclic chemistry》2000,37(4):791-798
The reaction of the alkylhydrazinoquinoxaline N‐oxides 2a‐d with dimethyl acetylenedicarboxylate gave the dimethyl 1‐alkyl‐1,5‐dihydropyridazino[3,4‐b]qumoxaline‐3,4‐dicarboxylates 3a‐d , whose reaction with nitrous acid effected the C4‐oxidation to afford the dimethyl 1‐alkyl‐4‐hydroxy‐1,4‐dihydropyridazino‐[3,4‐b]quinoxaline‐3,4‐dicarboxylates 4a‐d , respectively. The reaction of compounds 4a‐d with 1,8‐diazabicyclo[5.4.0]‐7‐undecene in ethanol provided the ethyl 1‐alkyl‐4‐oxo‐1,4‐dihydropyridazino[3,4‐b]quinoxa‐line‐3‐carboxylates 5a‐d , while the reaction of compounds 4a‐d with potassium hydroxide furnished the 1‐alkyl‐4‐oxo‐1,4‐dihydropyridazino[3,4‐b]quinoxaline‐3‐carboxylic acids 6a‐d , respectively. Compounds 6c,d were also obtained by the reaction of compounds 5c,d with potassium hydroxide, respectively. 相似文献
4.
Yoshihiro Ohta Makoto Karasawa Tetsurou Niiyama Akihiro Yokoyama Tsutomu Yokozawa 《Journal of polymer science. Part A, Polymer chemistry》2014,52(3):360-365
Well‐defined poly(3‐alkyl‐4‐benzamide) was synthesized by means of chain‐growth condensation polymerization of phenyl 3‐octyl‐4‐(4‐octyloxybenzyl(OOB)amino)benzoate ( 1c ) from initiator 2 , followed by removal of the OOB groups on amide nitrogen of poly 1c . Polymerization of 1c with phenyl 4‐(trifluoromethyl)benzoate ( 2b ) in the presence of 1,1,1,3,3,3‐hexamethyldisilazide (LiHMDS) and LiCl in THF at ?10 °C gave poly 1c with a narrow molecular weight distribution (Mw/Mn ≤ 1.08) and a well‐defined molecular weight (Mn = 4480–12,700) determined by the feed ratio of monomer to initiator (from 10 to 30). The OOB groups of poly 1c were removed with H2SO4 to give the corresponding N‐unsubstituted poly(p‐benzamide) (poly 1c′ ) with low polydispersity. The solublity of poly 1c′ in polar organic solvents was dramatically higher than that of poly(p‐benzamide), demonstrating that introduction of an alkyl group on the aromatic ring is very effective for improving the solubility of poly(p‐benzamide). © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 360–365 相似文献
5.
Evgeniya Leonova Mihail Makarov Zinaida Klemenkova Irina Odinets 《Helvetica chimica acta》2010,93(10):1990-1999
The aldol‐crotonic condensation reactions of N‐alkyl‐ and NH‐piperidin‐4‐one derivatives with (hetero)aromatic aldehydes promoted by Lewis acids or bases were examined. This comparative study has revealed three effective catalytic systems based on Lewis acids, i.e., LiClO4 and MgBr2 (in the presence of tertiary amine), and BF3⋅Et2O, for the synthesis of N‐alkyl‐substituted 3,5‐bis(heteroarylidene)piperidin‐4‐ones, including those bearing acid‐ or base‐labile groups both in the (hetero)aromatic groups and in the alkyl substituent at the N‐atom. The highest reaction rate was observed for LiClO4‐mediated synthesis. Both MgBr2‐ and LiClO4‐mediated syntheses were inefficient in the case of NH‐piperidin‐4‐one, while BF3⋅Et2O provided the final compounds in high yields. This catalyst is especially advantageous as it allows simultaneous condensation and deprotection in the case of O‐protected piperidin‐4‐one. 相似文献
6.
Treatment of methyl 2-(1-hydroxyalkyl)prop-2-enoates 1 with conc. HBr solution afforded methyl (Z)-2-(bromomethyl)alk-2-enoates 2 , which were transformed regioselectively into N-substituted methyl (E)-2- (aminomethyl)alk-2-enoates 3 (SN2 reaction) and into N-substituted methyl 2-(1-aminoalkyl)prop-2-enoates 4 (SN2′ reaction). Regiocontrol of nucleophilic attack by amine was accomplished simply by choice of solvent, the SN2 reaction occurring in MeCN and the SN2′ reaction in petroleum ether. Hydrolysis and lactamization afforded β-lactams 7 and 8 , containing an exocyciic alkylidene and methylidene group at C(3), respectively. 相似文献
7.
Fuyi Zhang Bruno Bernet Véronique Bonnet Olivier Dangles Francisco Sarabia Andrea Vasella 《Helvetica chimica acta》2008,91(4):608-617
Chitosan ( 1 ) was prepared by basic hydrolysis of chitin of an average molecular weight of 70000 Da, 1H‐NMR spectra indicating almost complete deacetylation. N‐Phthaloylation of 1 yielded the known N‐phthaloylchitosan ( 2 ), which was tritylated to provide 3a and methoxytritylated to 3b . Dephthaloylation of 3a with NH2NH2?H2O gave the 6‐O‐tritylated chitosan 4a . Similarly, 3b gave the 6‐O‐methoxytritylated 4b . CuSO4‐Catalyzed diazo transfer to 4a yielded 95% of the azide 5a , and uncatalyzed diazo transfer to 4b gave 82% of azide 5b . Further treatment of 5a with CuSO4 produced 2‐azido‐2‐deoxycellulose ( 7 ). Demethoxytritylation of 5b in HCOOH gave 2‐azido‐2‐deoxy‐3,6‐di‐O‐formylcellulose ( 6 ), which was deformylated to 7 . The 1,3‐dipolar cycloaddition of 7 to a range of phenyl‐, (phenyl)alkyl‐, and alkyl‐monosubstituted alkynes in DMSO in the presence of CuI gave the 1,2,3‐triazoles 8 – 15 in high yields. 相似文献
8.
A series of 3‐(3‐hydroxyphenyl)‐4‐alkyl‐3,4‐dihydrobenzo[e][1,3]oxazepine‐1,5‐dione compounds with general formula CnH2n+1CNO(CO)2C6H4(C6H4OH) in which n are even parity numbers from 2 to 18. The structure determinations on these compounds were performed by FT‐IR spectroscopy which indicated that the terminal alkyl chain attached to the oxazepine ring was fully extended. Conformational analysis in DMSO at ambient temperature was carried out for the first time via high resolution 1H NMR and 13C NMR spectroscopy. 相似文献
9.
Yoshiko Okada Shinobu Kishi Yasuko Shishido Masako Kato 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(5):m171-m173
Dichloro(4,4′‐dipentyl‐2,2′‐bipyridine‐κ2N,N′)platinum(II), [PtCl2(C20H28N2)], adopts a discrete π–π stacking structure, where the alkyl chains are located in a random manner. In contrast, dichloro(4,4′‐diheptyl‐2,2′‐bipyridine‐κ2N,N′)platinum(II), [PtCl2(C24H36N2)], forms a layer structure comprised of alkyl chain layers and paired coordination sites, as observed for analogous complexes with longer alkyl chains. 相似文献
10.
ortho‐Benzoxylation of N‐Alkyl Benzamides with Aromatic Acids Catalyzed by Ruthenium(II) Complex
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Kishor Padala Dr. Masilamani Jeganmohan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(14):4092-4097
A highly regioselective ortho‐benzoxylation of N‐alkyl benzamides with aromatic acids in the presence of [{RuCl2(p‐cymene)}2], AgSbF6, and (NH4)2S2O8 in 1,2‐dichloroethane at 100 °C for 24 h affording ortho‐benzoxylated N‐alkyl benzamides by C?H bond activation is described. Further, Ru‐catalyzed alkenylation is done at the ortho C?H bond of benzoxylated N‐alkyl benzamides with alkenes in water solvent. Subsequently, the benzoxyl moiety of N‐alkyl benzamides was converted into a hydroxyl group in the presence of base or acid. A possible reaction mechanism was proposed to account for the present coupling reaction. 相似文献
11.
Walid Fathalla Pavel Pazdera Michal ajan Jaromír Marek 《Journal of heterocyclic chemistry》2002,39(6):1145-1152
Regioselective reactions of morpholine‐1‐carbothioic acid (2‐phenyl‐3H‐quinazolin‐4‐ylidene) amide ( 1 ) with electrophiles and nucleophiles were studied. The compound ( 1 ) reacts with alkyl halides in basic medium to afford S‐substituted isothiourea derivatives, with amines to give 1,1‐disubstituted‐3‐(2‐phenyl‐3H‐quinazolin‐4‐ylidene) thioureas and l‐substituted‐3‐(2‐phenyl‐quinazolin‐4‐yl) thioureas via transami‐nation reaction. The reaction of ( 1 ) with amines in the presence of H2O2 provided N4‐disubstituted‐N'4‐(2‐phenylquinazolin‐4‐yl)morpholin‐4‐carboximidamide via oxidative desulfurization. Estimation of reactivity sites on ( 1 ) was supported using the ab initio (HF/6‐31G**) quantum chemistry calculations. The ir, 1H nmr, 13C nmr, mass spectroscopy and x‐ray identified the isolated products. 相似文献
12.
Fangzhong Hu Xinxin Cheng Zixia Niu Xiaobing Yang Dan Li Lei Wan Junxiao Li Bin Liu Xiaomao Zou Huazheng Yang Bin Li 《Journal of heterocyclic chemistry》2015,52(3):793-801
A series of 3‐phenyl benzo[d][1,2,3]triazin‐4(3H)‐one derivatives were synthesized through the condensation of phenol E and alkyl (alkenyl, alkynyl) chlorides (bromides, iodide) or alkyl chloroacetates or N‐alkyl chloroacetamides using K2CO3 as the acid acceptor in N,N‐dimethylformamide. Phenol E was prepared from starting material, 5‐amino‐2‐chloro‐4‐fluorophenyl ethyl carbonate, in four steps involving in amidation, reduction, diazotization, and deprotecting‐group reaction. The herbicidal activities of the title compounds were tested against two dicotyledonous plants and two monocotyledonous plants, in which some of them exhibited high herbicidal activities against two dicotyledonous plants in preemergence and postemergence treatments. Moreover, when the dosage was decreased to 180 and 90 g/ha, compounds F1 , F8 , and F9 showed highly selective inhibitory activities against amaranth pigweed, alfalfa, asteraceae, field sowthistle, morning glory, purslane, and velvetleaf in postemergence treatment but had no herbicidal efficacy on rape except F1 , suggesting that it be possible to find a kind of herbicides to inhibit dicotyledonous weeds in the field of dicotyledonous crops with the same genus as aforementioned weeds. 相似文献
13.
Isoprene polymerization with indolide‐imine supported rare‐earth metal alkyl and amidinate complexes
Yi Yang Qiaoyi Wang Dongmei Cui 《Journal of polymer science. Part A, Polymer chemistry》2008,46(15):5251-5262
Reaction of 7‐{(N‐2,6‐R)iminomethyl)}indole ( HL1 , R = dimethylphenyl; HL2 , R = diisopropylphenyl) and rare‐earth metal tris(alkyl)s, Ln(CH2SiMe3)3(THF)2, generated new rare‐earth metal bis(alkyl) complexes LLn(CH2SiMe3)2(THF) [L = L1: Ln = Lu ( 1a ), Sc ( 1b ); L = L2: Ln = Lu ( 3a ), Sc ( 3b )] and mono(alkyl) complexes L22Lu(CH2SiMe3) ( 4a ). Treatment of alkyl complexes 1a and 4a with N,N′‐diisopropylcarbodiimide afforded the corresponding amidinates L1Lu{iPr2NC(CH2SiMe3)NiPr2}2 ( 2a ) and L22Lu{iPr2NC(CH2SiMe3)NiPr2} ( 5a ), respectively. These new rare‐earth metal alkyls and amidinates except 4a in combination with aluminum alkyls and borate generated efficient homogeneous catalysts for the polymerization of isoprene, providing high cis‐1,4 selectivity and high molar mass polyisoprene with narrow molar mass distribution (Mn = 2.65 × 105, Mw/Mn = 1.07, cis‐1,4 98.2%, −60 °C). The environmental hindrance around central metals arising from the bulkiness of the ligands, the Lewis‐acidity of rare‐earth metal ions, the types of aluminum tris(alkyl)s and borate, and polymerization temperature influenced significantly on both the catalytic activity and the regioselectivity. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5251–5262, 2008 相似文献
14.
Elena I. Klimova Tatiana Klimova Marcos Flores Alamo José M. Méndez Stivalet Lena Ruíz Ramírez Leon V. Backinowsky Marcos Martínez García 《Journal of heterocyclic chemistry》2011,48(2):441-448
The reactions of α‐ferrocenylmethylidene‐β‐oxocarboxylates ( 1 , 2 , 3a , and 3b ) with N‐methyl‐ and N‐(2‐hydroxyethyl)hydrazines ( 5a , 5b ) afford ethyl 1‐alkyl‐5‐aryl(methyl)‐3‐ferrocenylpyrazole‐4‐carboxylates ( 6a , 6b , 6c , 6d , 6e ) (~50%) and N‐alkylhydrazine insertion products, viz., ethyl (N′‐acyl‐N′‐alkylhydrazino)‐3‐ferrocenylpropanoates ( 7a , 7b , 7c , 7d , 7e ) (~20%) and 1‐acyl‐2‐(N′‐alkyl‐N′‐ethoxycarbonylhydrazino)‐2‐ferrocenylethanes ( 8a , 8b , 8c , 8d , 8e ) (~10%). The structures of the compounds obtained were established based on the spectroscopic data and X‐ray diffraction analysis (for pyrazoles 6a and 6b ). J. Heterocyclic Chem., (2011). 相似文献
15.
Mohammad Navid SoltaniRad Ali Khalafi‐Nezhad Somayeh Babamohammadi Somayeh Behrouz 《Helvetica chimica acta》2010,93(12):2454-2466
A convenient and efficient method for a one‐pot conversion of N‐alkylisatins to N‐alkylisatin O‐alkyloximes 7a – 7n as potential chemotherapeutic agents is described (Scheme) (isatin=1H‐indole‐2,3‐dione). In this method, the microwave‐assisted three‐component reaction of N‐alkylisatins 8 , hydroxylamine hydrochloride, and diverse alkyl halides in the presence of K2CO3 and Bu4NBr furnishes the corresponding N‐alkylisatin O‐alkyloximes under solvent‐free condition in short times (2–10 min) and good to excellent yields (62–83%). The O‐alkylation of in situ generated isatin oximes with alkyl halides was achieved regioselectively, and (Z)‐O‐alkyloximes were produced dominantly. PM3 Semi‐empirical quantum‐mechanic calculations were performed to rationalize the evidences, and the calculations indicated a lower heat of formation for the (Z)‐O‐alkyloximes. 相似文献
16.
Janet E. Del Bene 《Journal of computational chemistry》1981,2(2):200-206
Hydrogen bonding of uracil with water in excited n → π* states has been investigated by means of ab initio SCF -CI calculations on uracil and water–uracil complexes. Two low-energy excited states arise from n → π* transitions in uracil. The first is due to excitation of the C4? O group, while the second is associated with excitation of the C2? O group. In the first n → π* state, hydrogen bonds at O4 are broken, so that the open water–uracil dimer at O4 dissociates. The “wobble” dimer, in which a water molecule is essentially free to move between its position in an open structure at N3? H and a cyclic structure at N3? H and O4 in the ground state, collapses to a different “wobble” dimer at N3? H and O2 in the excited state. The third dimer, a “wobble” dimer at N1? H and O2, remains intact, but is destabilized relative to the ground state. Although hydrogen bonds at O2 are broken in the second n → π* state, the three water–uracil dimers remain bound. The “wobble” dimer at N1? H and O2 changes to an excited open dimer at N1? H. The “wobble” dimer at N3? H and O4 remains intact, and the open dimer at O4 is further stabilized upon excitation. Dimer blue shifts of n → π* bands are nearly additive in 2:1 and 3:1 water:uracil structures. The fates of the three 2:1 water:uracil trimers and the 3:1 water:uracil tetramer in the first and second n → π* states are determined by the fates of the corresponding excited dimers in these states. 相似文献
17.
Runze Mao Jonathan Balon Prof. Dr. Xile Hu 《Angewandte Chemie (International ed. in English)》2018,57(41):13624-13628
Alkyl aryl ethers are an important class of compounds in medicinal and agricultural chemistry. Catalytic C(sp3)?O cross‐coupling of alkyl electrophiles with phenols is an unexplored disconnection strategy to the synthesis of alkyl aryl ethers, with the potential to overcome some of the major limitations of existing methods such as C(sp2)?O cross‐coupling and SN2 reactions. Reported here is a tandem photoredox and copper catalysis to achieve decarboxylative C(sp3)?O coupling of alkyl N‐hydroxyphthalimide (NHPI) esters with phenols under mild reaction conditions. This method was used to synthesize a diverse set of alkyl aryl ethers using readily available alkyl carboxylic acids, including many natural products and drug molecules. Complementarity in scope and functional‐group tolerance to existing methods was demonstrated. 相似文献
18.
Wolfgang Beck Wolf Peter Fehlhammer Klaus Feldl Thomas M. Klaptke Gernot Kramer Peter Mayer Holger Piotrowski Peter Pllmann Walter Ponikwar Thomas Schütt Erich Schuierer Martin Vogt 《无机化学与普通化学杂志》2001,627(8):1751-1758
The crystal structures of the monomeric palladium(II) azide complexes of the type L2Pd(N3)2 (L = PPh3 ( 1 ), AsPh3 ( 2 ), and 2‐chloropyridine ( 3 )), the dimeric [(AsPh4)2][Pd2(N3)4Cl2] ( 4 ), the homoleptic azido palladate [(PNP)2][Pd(N3)4] ( 5 ) and the homoleptic azido platinates [(AsPh4)2][Pt(N3)4] · 2 H2O ( 6 ) and [(AsPh4)2][Pt(N3)6] ( 7 ) were determined by X‐ray diffraction at single crystals. 1 and 2 are isotypic and crystallize in the triclinic space group P1. 1 , 2 and 3 show terminal azide ligands in trans position. In 4 the [Pd2(N3)4Cl2]2– anions show end‐on bridging azide groups as well as terminal chlorine atoms and azide ligands. The anions in 5 and 6 show azide ligands in equal positions with almost local C4h symmetry at the platinum and palladium atom respectively. The metal atoms show a planar surrounding. The [Pt(N3)6]2– anions in 7 are centrosymmetric (idealized S6 symmetry) with an octahedral surrounding of six nitrogen atoms at the platinum centers. 相似文献
19.
Grzegorz Mlosto Magorzata Celeda G.K.Surya Prakash GeorgeA. Olah Heinz Heimgartner 《Helvetica chimica acta》2000,83(4):728-738
The reaction of 1,4,5‐trisubstituted 1H‐imidazole 3‐oxides 1 with Ac2O in CH2Cl2 at 0 – 5° leads to the corresponding 1,3‐dihydro‐2H‐imidazol‐2‐ones 4 in good yields. In refluxing Ac2O, the N‐oxides 1 are transformed to N‐acetylated 1,3‐dihydro‐2H‐imidazol‐2‐ones 5 . The proposed mechanisms for these reactions are analogous to those for N‐oxides of 6‐membered heterocycles (Scheme 2). A smooth synthesis of 1H‐imidazole‐2‐carbonitriles 2 starting with 1 is achieved by treatment with trimethylsilanecarbonitrile (Me3SiCN) in CH2Cl2 at 0 – 5° (Scheme 3). 相似文献
20.
Andrey I. Poddel'sky Yury A. Kurskii Alexandr V. Piskunov Nikolay V. Somov Vladimir K. Cherkasov Gleb A. Abakumov 《应用有机金属化学》2011,25(3):180-189
New triphenylantimony(V) o‐amidophenolates (AP‐Me,Et)SbPh3 (1) and (AP‐Me,iPr)SbPh3 (2) with unsymmetrically substituted N‐aryl groups and (AP‐Et,Et)SbPh3 (3) with symmetrical N‐aryl group {AP‐R1,R2 is 4,6‐di‐tert‐butyl‐N‐[2‐alkyl(R1),6‐alkyl(R2)‐phenyl]‐o‐amidophenolate dianion} were synthesized and characterized in detail. Complexes were examined for dioxygen activity. The unsymmetrical complexes 1 and 2 were found to form different geometrical isomers (A and B) of spiroendoperoxides [L‐R1,R2(O2)]SbPh3 (4 and 5, respectively) with different dispositions of peroxide group and N‐aryl fragment (methyl and peroxide group are on the same side of the molecule in the less shielded isomer A, and on different sides in the more hindered isomer B). The isomer A prevails over isomer B, reflecting the possibility of steric control on the dioxygen‐binding reaction. Complex 3, where R1 = R2 = Et, formed the isomers 6A and 6B as 50:50. The ratio 4A:4B was 60:40 (for methyl‐ethyl containing complex 4) and it increased up to 80:20 for methyl‐isopropyl‐containing 5. The molecular structure of isomers 4A and 4B was confirmed by X‐ray analysis. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献