Condensation of Schiff bases with 2-oxazolin-5-ones: simultaneous introduction of arylidene and amino moieties

1982 ◽  
Vol 60 (3) ◽  
pp. 317-322 ◽  
Author(s):  
Arya K. Mukerjee ◽  
Pradeep Kumar

Schiff bases condense with 2-oxazolin-5-ones having a C-4 methylene and/or C-2 methyl group, and the reaction in glacial acetic acid, containing freshly fused sodium acetate, produces 4-arylidene- and/or 2-styryl-2-imidazoline-5-ones as a result of simultaneous introduction of arylidene and amino moieties.

2008 ◽  
Vol 59 (1) ◽  
pp. 41-44
Author(s):  
Maria-Daniela Sofei ◽  
Maria Ilici ◽  
Valentin Badea ◽  
Carol Csunderlik ◽  
Vasile-Nicolae Bercean

The synthesis of 1H-3-aryl-7-ethoxycarbonyl-6-methyl-pyrazolo[5,1-c][1,2,4]triazoles (2) was carried out by cyclization of 1H-5-arylidenehydrazino-4-ethoxycarbonyl-3-methyl-pyrazoles (1) in the presence of bromine using glacial acetic acid as solvent and sodium acetate as base. The new nine obtained compounds were characterized by IR and NMR spectroscopy and mass spectrometry.


1952 ◽  
Vol 30 (9) ◽  
pp. 687-693 ◽  
Author(s):  
T. R. Ingraham ◽  
C. A. Winkler

Rate curves have been determined for the reaction of ammonium nitrate with formaldehyde in glacial acetic acid solution at 25 °C., 35 °C., 45 °C., and 55 °C. over a range of Initial mole ratios (formaldehyde: ammonia) of 0.75:1 to 9.0:1. Data obtained at 25 °C. show a definite induction period in the formation of hexamine. The length of the induction period is not changed by increasing ammonium nitrate concentrations above the theoretical (1.5:1), but may be appreciably shortened by initial additions of excess formaldehyde or of sodium acetate. From 35 °C. upward, the induction period is not apparent. The order of the reaction with respect to formaldehyde has been determined from initial rate data, and an activation energy calculated. The reactions in general appear analogous to those found in slightly acid aqueous systems.


1978 ◽  
Vol 31 (11) ◽  
pp. 2505 ◽  
Author(s):  
DJ Brown ◽  
T Nagamatsu

Pyrimidin-4-ylhydrazines and simple orthoesters are used in combination (1) to give N-ethoxyalkyl-idene-N'-pyrimidinylhydrazines (2) and thence s-triazolo[4,3-c]pyrimidine (3a) and its 3-, 5-, 7- or 8-alkylated derivatives (3b-s). In glacial acetic acid, these undergo rearrangement into the corresponding s-triazolo[1,5-c]pyrimidines (5) via the acylaminoalkenyltriazoles (4); in aqueous buffers, these reactions stop at the triazoles (4) except in the presence of a 7-methyl group which stimulates completion of the sequence. The ring-fission step, (3) → (4), is retarded markedly by 5- and/or 8-methyl groups but accelerated slightly by 3- and/or 7-alkyl groups; the slower ring-fission of triazolo[1,5-c]-pyrimidines (5) to the same triazoles (4) is retarded by 2-, 5- or 8-alkylation and precluded totally by a 7-methyl group. The recorded u.v. and N.M.R. spectra afford a ready means of distinguishing between the systems (3)-(5).


2013 ◽  
Vol 2 (3) ◽  
pp. 33-39 ◽  
Author(s):  
M Roganda L Lumban Gaol ◽  
Roganda Sitorus ◽  
Yanthi S ◽  
Indra Surya ◽  
Renita Manurung

Utilization of empty fruit bunches of oil palm in Indonesia is still very low, so it should be developed further. One of them by researching the manufacture of cellulose acetate from oil palm empty fruit bunches. The process used in this study is the cellanase with α-cellulose materials. Stages reaction is activation, acetylation, hydrolysis, neutralization and drying. Activation in thethree-neck flask with the addition of 50 ml of glacial acetic acid and stirredfor 3 hour,then added 15 ml of acetic acid anhydride as acetylation agent. Acetylation performed with the variation of time, 2, 2.5, 3, 3.5 hours.  In the hydrolysis step, add 2 ml of water and5 ml of glacial acetic acid. The reaction lasted for 30 minutes, then added 1 g of sodium acetate for neutralization, neutralization lasts for 5 minutes.  Then do the washing up to the smell of acetic acid is lost, and the last stage is the drying is done with a temperature below 50 oC.  The resulting products are then analyzed the degree of substitution, melting point, and then carried out FTIR analysis.  The results obtained when the optimum conditions for the acetylation reaction is 2.5 - 3 hours.


Author(s):  
Esraa M Ali ◽  
Ahmed W. Naser ◽  
Muthanna S. Farhan

Objective: In the present work, a variety of new heterocyclic compounds namely aza-β- lactam, cyclicimides, 1,3-thiazole, and 1,2,4-triazole.Methods: Procedure includes the synthesis of aza-β- lactam, cyclic imides, 1,3-thiazole, and 1,2,4-triazole. The synthesis was carried out in eleven steps using N-(Ñ-substituted phenylglycyl) saccharin derivatives (1a,b) as a starting material and converted to benzoic acid derivatives (2a,b) and then to ester derivatives (3a,b), which finally convers to benzohydrazide derivatives (4a,b). The cyclization of (4a,b) with carbon disulfide and hydrazine hydrate (80%) in the presence of potassium hydroxide gives 1,2,4-triazole compounds (5a,b), and subsequently (5a,b) derivatives reacted with different aromatic aldehydes in the presence of few drops of glacial acetic acid to give Schiff bases (6a-f). Compounds (7a-b) was prepared by the reaction of compounds (4a,b) with chloroacetyl chloride. 1,3-thiazole derivatives (8a,b) were synthesized through the cyclization of compounds (7a,b) with thiourea. Schiff bases (9a-f) were obtained by condensation of (4a,b) with different aromatic aldehydes in the presence of few drops of glacial acetic acid. Aza-β-lactam compounds (10a-f) were prepared by the cycloaddition of Schiff-bases (9a-f) with phenyl isocyanate through [2+2] cycloaddition reaction. Reaction (4a,b) with various acid anhydrides in presence of acetic acid gave the corresponding cyclic imide (11a-f). The newly prepared.Results: The results showed that compounds (5a) and (10e) have a good activity against Gram-positive bacterium and no activity against Gram-negative bacterium, compared to standard drugs (ciprofloxacin and amoxicillin), while compounds (8a) and (6b) have a high activity against fungi, compared to standard drugs (metronidazole benzoate), and the other tested compounds have low-to-moderate activity.Conclusion: 1,2,4-triazole is a most potent assemblage of Gram-positive bacterium retardants and cyclic imides are a most potent assemblage of fungi retardants.


Author(s):  
Gilbert Y. Kennedy

Munro Fox (1926, Addendum, p. 219) described a method of preparation of chlorocruoroporphyrin from the blood of the marine polychaete worm Spirographis. This was based upon the very troublesome method of Nencki & Zaleski (1900), which is time-consuming and wasteful. Furthermore, Spirographis is not easily obtainable in this country. Lemberg & Parker (1952) started with protoporphyrin, and by careful oxidation with potassium permanganate in acetone obtained a solution which gaVe mixed crystals of chlorocruoroporphyrin and diformyldeuteroporphyrin esters. Purification was by fractional chromatography. The procedure to be described here is simple and rapid, and could easily be carried out in one day by a biologist requiring a small sample of the porphyrin. The two methods mentioned above would not come into this category.This work was done at the Plymouth Laboratory, and I am very grateful to Mr T. R. Tozer of that laboratory for so kindly obtaining the animals for me and extracting the blood.The polychaete worms Myxicola infundibulum, Sabella pavonina and Branchiomma vesiculosum are all readily obtained from the muddy shores of the Salcombe estuary, especially on the Salstone. Blood was taken directly from the vessels of about 100 assorted worms by syringe, and squirted as it was removed from the worms into a mixture of peroxide-free ether (3 parts) and ‘Analar’ glacial acetic acid (1 part). After all the blood had been added, the mixture was well shaken and allowed to stand in the ice-chest for 30 min. The acetic acid was then washed out with distilled water, the first few washings containing a little sodium acetate to avoid washing out of the pigment, and the remaining solution of chlorocruorohaematin dried roughly by filtering through ether-soaked paper into a distilling flask and evaporated to dryness. 100 ml. of a 50% solution of hydrazine hydrate in glacial acetic acid were then added, and the mixture heated on a water-bath at 90° C. for 10 min.


2020 ◽  
Vol 8 (1) ◽  
pp. 12-18
Author(s):  
Alya A. Dawood ◽  
Shireen R. Mmohammed ◽  
Mohammed Mahmoud

Series of new Schiff bases and their derivatives (Oxazepine) have been synthesized during two steps. The first step synthesis of imines derivatives (1-10) by the condensation reaction of 1, 7-diaminohepatane and 1,8-diaminooctane with different substituted aromatic aldehydes by using glacial acetic acid as catalyst. The second step includes reaction of the prepared Schiff bases derivatives with phathalic anhydride in dry benzene to obtain   seven-membered heterocyclic ring derivatives (11-15).  The biological activities of some prepared compounds were also studied against different kinds of bacteria. The new derivatives were confirmed by suing a range of experimental techniques including 1HNMR, 13C NMR, IR and Mass spectra.


2018 ◽  
Vol 4 (1) ◽  
Author(s):  
M. Topan Darmawan ◽  
Muthia Elma ◽  
M. Ihsan

Selulosa asetat merupakan senyawa turunan selulosa yang sering digunakan sebagai serat, membran, dan film fotografi dalam industri. Tujuan dari penelitian ini adalah mengetahui pengaruh waktu asetilasi terhadap karakter selulosa asetat yang dihasilkan. Adapun proses yang digunakan dalam penelitian ini adalah proses cellanase dengan bahan baku tandan kosong kelapa sawit (TKKS). Tahapan reaksinya adalah aktivasi, asetilasi, dan hidrolisis. Aktivasi dilakukan di dalam labu leher tiga dengan penambahan asam asetat glacial 50 mL dan diaduk selama 3 jam pada kecepatan 125 rpm. Selanjutnya ditambahkan asetat anhidrida 15 mL sebagai agen asetilasi. Asetilasi dilakukan dengan variasi waktu, 2; 2,5; 3; dan 3,5 jam. Pada tahapan hidrolisis, ditambahkan air 2 mL dan asam asetat glacial 5 mL. Reaksi berlangsung selama 30 menit. Selanjutnya ditambahkan 1 gram natrium asetat untuk netralisasi yang berlangsung selama 5 menit. Kemudian dilakukan pencucian sampai bau asam asetat hilang. Tahapan terakhir adalah pengeringan yang dilakukan dengan suhu 55ºC selama 6 jam. Produk yang dihasilkan kemudian dianalisis kadar air, kadar asetil, rendemen dan gugus fungsi menggunakan analisa FTIR. Selulosa asetat yang terbaik diperoleh pada waktu asetilasi selama 2,5 jam dengan  kadar  asetil  40,36%, kadar  air  4.43%,  dan  rendemen 153,8%.Kata kunci: cellanase, selulosa, selulosa asetat. Cellulose acetate is a cellulose derivative which is often used as a fiber, membrane, and photographic film in industry. The  objectives  of  this  study  were  to determine the effect of acetylation time on the character of cellulose acetate. The process used in this study is the process of cellanase with α-cellulose of empty palm oil bunches materials. Stages of reaction are activation, acetylation, and hydrolysis. Activation was performed in a three-neck flask with the addition of 50 mL glacial acetic acid and stirred for 3 hours at 125 rpm. Then added 15 mL acetic anhydride as acetylation agent. Acetylation was performed by varying the time, 2; 2.5; 3; And 3.5 hours. At the hydrolysis stage, 2 mL of water and 5 mL glacial acetic acid were added. The reaction lasts for 30 minutes. Then added 1 gram of sodium acetate for neutralization lasts 5 minutes. then do the washing up to the smell of acetic acid disappeared. The final stage is the drying is done at a temperature of 55ºC for 6 hours. The resulting product was then analyzed for water content, acetyl content, rendement and functional groups using FTIR analysis. Cellulose acetate are best obtained at the time of acetylation for 2.5 hours with acetyl content of 40.36%, water content 4:43%, and a yield of 153.8%.Keywords: acetate cellulose, cellanase, cellulose.


1971 ◽  
Vol 49 (10) ◽  
pp. 1588-1597 ◽  
Author(s):  
Eberhard Kiehlmann ◽  
Pui-Wah Loo

The reactivity of a series of 14 aliphatic ketones in the crossed aldol condensation with chloral has been studied in glacial acetic acid and in dimethoxyethane. The reaction is irreversible and not accompanied by dehydration of the resulting 1,1,1-trichloro-3-hydroxy-4-alkanones. Except for butanone, condensation occurs preferentially at the least-hindered position of an unsymmetrical ketone. The α-methyl/α-methylene condensation product ratio obtained from ketones of the general formula RCH2COCH3 is higher in acetic acid than in dimethoxyethane as solvent when sodium acetate is used as catalyst. The steric size and chain length of the alkyl groups of methyl alkyl ketones have a marked effect on the reactivity of the α-methyl group toward chloral. Condensation at the α-methylene group results in the formation of diastereomeric ketols which epimerize under the preparative reaction conditions.


2021 ◽  
Vol 32 (3) ◽  
pp. 8
Author(s):  
Mohammed Ibrahim Sultan ◽  
Ahmed M. Abdula ◽  
Rana I. Faeq ◽  
Mahdi F. Radi

A new series of pyrazoline derivatives (3-10) have been synthesized and characterized on the basis of FT-IR, 1H-NMR, and Mass techniques. 1-(4-Aminophenyl)-3-(pyridin-4-yl)prop-2-en-1-one (1) as a starting material was prepared by the reaction of 4-aminoacetophenone and 4-pyridinecarboxaldehyde in ethanol, using sodium hydroxide as a catalyst. Pyrazoline derivatives 2 was obtained via the cyclization reaction of compound 1 by the action of hydrazine hydrate 80% in ethanol. The target derivatives (3-8) were obtained by the reaction of pyrazoline derivative (2) with the corresponding aldehyde in ethanol. The novel pyrazoline derivatives 9 and 10 were synthesized by the reaction of pyrazoline derivative 2 with the corresponding anhydride (maleic or phthalic anhydride) in presence of anhydrous sodium acetate in glacial acetic acid. The synthesized derivatives were screened against several bacterial strains: Staphylococcus aureus, Staphylococcus espidermididis, Escherichia coli, Klebsiella and Candida albicans. The synthesized compounds showed promising bio-activity compared with amoxicillin.


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