The presence of fluorine in biologically active compounds can impart a profound influence on their biological active. This influence has lead to the development of several potent agricultural and therapeutic agents[1]...The presence of fluorine in biologically active compounds can impart a profound influence on their biological active. This influence has lead to the development of several potent agricultural and therapeutic agents[1]. During the study on the reactions of 4 - ethoxyl - 1, 1, 1 -trifluoromathyl-3-butenone 1, we found which is a very useful building-block in synthesis of fluoro-containing heterocyclic compounds[2]. Compound 1 can react with perfluorophenyl hydrazine and afford 1- perfluorophenyl-5-trifluoromethyl- 5 -hydroxy-4, 5 -2H- pyrazole 2 in excellent yield. It’s structure is further supported by X-ray diffraction.展开更多
Reaction of indole-3-carboxaldehydes 4 with hydrazine derivatives and different substituted acid hydrazides afforded the corresponding hydrazine derivatives 5a-c and acid hydrazide derivatives 7-11 respectively. Conde...Reaction of indole-3-carboxaldehydes 4 with hydrazine derivatives and different substituted acid hydrazides afforded the corresponding hydrazine derivatives 5a-c and acid hydrazide derivatives 7-11 respectively. Condensation of indole-3-carboxaldehydes 4 with phenacyl bromide and thiourea gives 1,3-thiazol-2-amine derivative 18. On the other hand, reaction 4 with 3-acetylchromene-2-one afforded chalcone derivative 19. Compound 4 undergoing Knoevenagel condensation with cyanoacetamide, ethyl cyanoacetate, benzimidazol-2-ylacetonitrile, rhodanine-3-acetic acid, 2,3-dihydropyrimidin-4-one derivative and 2,4-dihydropyrazol-3-one afforded the compounds 20a,b, 22, 23, 27 and 28 respectively. The structure of the newly synthesized compounds has been confirmed by elemental analysis and spectra data. The antimicrobial activities of the some newly synthesized compounds were measured and showed that most of them have high展开更多
A new rhodamine derivative,N-(3-carboxy)acryloyl rhodamine B hydrazide(CARB),has been synthesized,and its unusual spectroscopic reaction with Cu2+ has been investigated.The derivative exhibits a rapid and reversible n...A new rhodamine derivative,N-(3-carboxy)acryloyl rhodamine B hydrazide(CARB),has been synthesized,and its unusual spectroscopic reaction with Cu2+ has been investigated.The derivative exhibits a rapid and reversible non-fluorescent absorption upon coordination to Cu2+,which is a rather unusual phenomenon for rhodamine B derivatives.Stoichiometric measurements using the Job's method and the molar ratio method reveal that one CARB molecule combines two Cu2+ ions,and the two Cu2+ ions play different roles:one opens the spirocyclic structure and the other quenches the fluorescence of the xanthene moiety.This reaction mechanism is supported by a comparative study on the model compound N-acryloyl rhodamine B hydrazide as well as by the density functional theory calculations.Furthermore,the absorption response of CARB is highly selective for Cu2+ over other common ions,which implies that CARB may be used as a colorimetric probe for the rapid visual detection of Cu2+.展开更多
A series of novel N-[（1-aryl-3-phenyl-pyrazol-4-yl）methylene]-2-（halo-o-hydroxyphenyl）hydrazide derivatives was synthesized and the antibacterial activity of each of them was evaluated. The supposed reaction mecha...A series of novel N-[（1-aryl-3-phenyl-pyrazol-4-yl）methylene]-2-（halo-o-hydroxyphenyl）hydrazide derivatives was synthesized and the antibacterial activity of each of them was evaluated. The supposed reaction mechanism of acquiring compounds 3a--3d is that catalytic activity is enhanced by the electron-donating groups of the first phenyl ring while decreased by electron-withdrawing groups of that ring. The result of preliminary bioassay shows that the lowest minimal inhibitory concentration（MIC） of the title compounds against Escherichia coli is 2 ℃g/mL. MIC values against Monilia albiean and Staphloeoeeus aureus are as low as 4 ~g/mL. They will be a series of potential antibacterial compounds against fungi and gram-negative bacteria.展开更多
基金The authors thank the National Natural Science Foundation ofChina (NNSFC) !(No. 29872051 and No 29672041 ) for financial support
文摘The presence of fluorine in biologically active compounds can impart a profound influence on their biological active. This influence has lead to the development of several potent agricultural and therapeutic agents[1]. During the study on the reactions of 4 - ethoxyl - 1, 1, 1 -trifluoromathyl-3-butenone 1, we found which is a very useful building-block in synthesis of fluoro-containing heterocyclic compounds[2]. Compound 1 can react with perfluorophenyl hydrazine and afford 1- perfluorophenyl-5-trifluoromethyl- 5 -hydroxy-4, 5 -2H- pyrazole 2 in excellent yield. It’s structure is further supported by X-ray diffraction.
基金Financial support was provided by the National Natural Science Foundation of China(21102173)the State Key Laboratory for Biology of Plant Diseases and Insect Pests(SKLOF201411)the President Science Foundation of South China Agricultural University(4200-K13014)
文摘Reaction of indole-3-carboxaldehydes 4 with hydrazine derivatives and different substituted acid hydrazides afforded the corresponding hydrazine derivatives 5a-c and acid hydrazide derivatives 7-11 respectively. Condensation of indole-3-carboxaldehydes 4 with phenacyl bromide and thiourea gives 1,3-thiazol-2-amine derivative 18. On the other hand, reaction 4 with 3-acetylchromene-2-one afforded chalcone derivative 19. Compound 4 undergoing Knoevenagel condensation with cyanoacetamide, ethyl cyanoacetate, benzimidazol-2-ylacetonitrile, rhodanine-3-acetic acid, 2,3-dihydropyrimidin-4-one derivative and 2,4-dihydropyrazol-3-one afforded the compounds 20a,b, 22, 23, 27 and 28 respectively. The structure of the newly synthesized compounds has been confirmed by elemental analysis and spectra data. The antimicrobial activities of the some newly synthesized compounds were measured and showed that most of them have high
基金supported by grants from the National Natural Science Foundation of China (20935005,90813032 & 20875092)National Basic Research Program of China (2010CB933502 & 2011CB935800)the Chinese Academy of Sciences
文摘A new rhodamine derivative,N-(3-carboxy)acryloyl rhodamine B hydrazide(CARB),has been synthesized,and its unusual spectroscopic reaction with Cu2+ has been investigated.The derivative exhibits a rapid and reversible non-fluorescent absorption upon coordination to Cu2+,which is a rather unusual phenomenon for rhodamine B derivatives.Stoichiometric measurements using the Job's method and the molar ratio method reveal that one CARB molecule combines two Cu2+ ions,and the two Cu2+ ions play different roles:one opens the spirocyclic structure and the other quenches the fluorescence of the xanthene moiety.This reaction mechanism is supported by a comparative study on the model compound N-acryloyl rhodamine B hydrazide as well as by the density functional theory calculations.Furthermore,the absorption response of CARB is highly selective for Cu2+ over other common ions,which implies that CARB may be used as a colorimetric probe for the rapid visual detection of Cu2+.
基金Supported by the National Natural Science Foundation of China（Nos.20976135, 21176194）.
文摘A series of novel N-[（1-aryl-3-phenyl-pyrazol-4-yl）methylene]-2-（halo-o-hydroxyphenyl）hydrazide derivatives was synthesized and the antibacterial activity of each of them was evaluated. The supposed reaction mechanism of acquiring compounds 3a--3d is that catalytic activity is enhanced by the electron-donating groups of the first phenyl ring while decreased by electron-withdrawing groups of that ring. The result of preliminary bioassay shows that the lowest minimal inhibitory concentration（MIC） of the title compounds against Escherichia coli is 2 ℃g/mL. MIC values against Monilia albiean and Staphloeoeeus aureus are as low as 4 ~g/mL. They will be a series of potential antibacterial compounds against fungi and gram-negative bacteria.
