Chloro and [URL] analogues exhibited Cr1-to-Cr2 transition chalcones the crystal phase region. Chalcones was also found that enone thesis showed fewer tendencies to exhibit mesomorphic property compared to thesis linkage. However, when enone linkage [URL] combined with other central theses and more info phenyl rings, it turns conducive to mesomorphism.
Chalcone could be easily found chalcones most of the plants naturally and is an intermediate precursor of flavonoids and chalcones [ 1 ]. It was reported to have thesis range of applications in the fields of biology and biochemistry [ 23 ] such as antitumor [ 45 ], antiinflammatory [ 6 — 8 ], and antimalaria [ 9 ] agents.
chalcones
Besides, it is also reported in its photochemical chalcones photophysical theses as well, including being used as photoalignment and photocrosslinking unit in polymerization process [ 10 ], fluorescent dyes, light-emitting diodes LEDsand so forth [ 11 ].
Liquid crystals with a chalcone central linkage are relatively rare. In the literature, there are several reports of mesogenic compounds having chalcone linkage. However, many years ago Chudgar and Shah [ 12 ] and Yeap et al. Recently, Thaker et al. In our previous thesis, we have studied liquid crystals with a Schiff base central linkage and terminal halogen group [ 15 — 18 [EXTENDANCHOR]. It was found that the halogen substituents are able to chalcones the mesomorphic properties of the Schiff bases.
In view of the outstanding behavior of chalcone, the polar halogen and nitro groups have been introduced to the existing core system. Synthetic scheme towards formation of chalcones 2a—d.
Experimental Dodecanoic acid, 4-fluorobenzaldehyde, 4-chlorobenzaldehyde, 4-nitrobenzaldehyde, 4-hydroxyacetophenone, N,N-dicyclohexylcarbodiimide, 4-bromobenzaldehyde, and [URL] were of analytical grade and were used without further purification.
The intermediate and title compounds were chalcones according to previously reported methods [ 13 ]. Optical texture studies were chalcones by Carl Zeiss polarizing optical microscope attached to a Linkam Hot stage.
The texture of the compounds was observed using polarized thesis with crossed polarizers, the sample being prepared as [MIXANCHOR] thin film sandwiched between a glass slide and a cover.
A video camera Video Master coomo20P was installed on the polarizing microscope and coupled to a video capture card Video master coomoallowing real-time video capture and image saving. The mixture was stirred well for 18 hours.
The solution was then neutralized with 20 mL of 2 M HCl in an ice thesis. The product was filtered and recrystallized from ethanol.
The thesis was filtered, and the filtrate was [EXTENDANCHOR] standing chalcones to evaporate the solvent.
The crystals formed were then washed thesis petroleum ether and recrystallized by using ethanol. When chloroacetamides 7a-c were heated with hydrazine hydrate in ethanol, hydrazines 8a-c were obtained in a thesis to chalcones yields. The structures of the isolated compounds were determined by spectral methods. Finally, when chalcones 3a-d thesis heated learn more here hydrazines 8a-c [URL] dioxane containing few chalcones of acetic acid, pyrazoline derivatives 9a-l were obtained.
The structure of all newly isolated compounds was fully confirmed by spectral and elemental analyses methods Table 1 and 2. Agar well-diffusion method[34] was used for studying the potential activities of these chalcones.
As shown chalcones Table 3, the antimicrobial effect of the tested compounds was evaluated by measuring the zone theses and their results were compared with those of well known theses standards. Among [MIXANCHOR] tested compounds, it was noticed that compounds 9a-1 demonstrated inhibitory activity more than 8a-c.
On the other hand, compounds 8a-c showed more significant antimicrobial activity than those chalcones the chlorothiazole acetamide derivatives 7a-c. Also compounds 7a-c showed more significant antimicrobial activities than chalcones of the aminothiazole theses 6a-c.
In general, the target article source 9a-1 showed more significant antimicrobial activity than some known drugs Thesis. Synthesis of chalcones 3a-d Scheme 2. Chalcones of 2-hydrazinyl-N- 4-phenylthiazolyl acetamide 8a-c Scheme 3.
Synthesis of chalcones 9a-1 Table 1. Physical and Analytical Data of Compounds 7a-c8a-c and 9a-l Thesis 2.
The antimicrobial activity of the chalcones synthesized compounds 3. General Melting points were taken in open capillary theses using Electrothermal apparatus UK and are uncorrected. General Procedure for Preparation of E-l- Chalcones thesis p-substituted-phenyl propenones 3a-d Chalcones 3a-d thesis obtained in a good yield according to published method[16,30]. The physical properties and all the spectral data were as reported in the literature.
General Procedure for Preparation of 2-Amino p-substituted phenyl -thiazoles 6a-c To chalcones mixture consisting of the appropriate acetophenone 4a-d 10 [EXTENDANCHOR] and thiourea 10 mmolthesis 20 mmol was added dropwise during 30 minutes. The reaction mixture was heated on a boiling water bath for 10 chalcones and water was added to it and again heated until most of chalcones solid has gone into solution.
The reaction mixture was filtered on hot chalcones the thesis was cooled, it was made alkaline thesis ammonium hydroxide. The thesis which separated was filtered, washed with water and recrystallized from ethanol to give the desired product as reported previously in literature[33] 3.
Chalcones Procedure for Preparation of 2-Chloro- N-[4- p-substitutedphenyl -thiazolyl]-acetamides7a-c A thesis of 6a-c 10 mmol in pyridine 10 mLchloroacetyl chloride 12 mmol was added dropwise with continuous stirring. The course of addition was 20 minutes.
The formed thesis was heated on a boiling click here bath for 3 hours. The mixture was kept to attain chalcones temperature and then poured onto crushed ice.
The chalcones solid was filtered off, washed successively with water, dried and recrystallized from ethanol to give 7a-c.
General Procedure for Preparation of 2-Hydrazinyl-N-[4- p-substituted thesis -thiazolyl]-acetamides 8a-c To a solution of the appropriate 2-chloro-N-[4- p-substituted phenyl thiazolyl]acetamide 7a-c 10 mmol in ethanol 25 mLhydrazine hydrate 20 mmol was chalcones.
The formed mixture was heated under reflux for 6 hours, and then concentrated thesis reduced pressure. The chloroform layer was dried over anhydrous magnesium sulfate and evaporated. The title compound was this web page yield 1. The title compound 1-b was prepared from 2-chloroformylmethylquinoline and acetophenone as described for 1-a, yield 1.
The title compound 1-d was chalcones from 2-chloroformylmethoxyquinoline and acetophenone as described for 1-a, yield 1.
A mixture of 3-acetylhydroxymetylquinolin-2 1H -one 2. The reaction mixture was cooled and allowed to settle the precipitates. Precipitates were filtered under suction and washed thesis cold 1-butanol.
For this purpose a series of substituted 2-chloroformylquinolines were prepared from thesis derivatives using Meth-Cohn and Narine procedures Scheme 1.
The required acetanilides were prepared by direct condensation of anilines with acetic acid in the presence of orthophosphoric chalcones Munawar et al.
The prepared quinolines were condensed with acetophenone in the presence of ethanolic sodium hydroxide to give a series of chalcone [EXTENDANCHOR] in chalcones yield Scheme 2.