Open Access Short Research Article

Synthesis of New 4-(dimethylamino)benzhydrazide Derivatives and Their Cyclization to 1,3-benzothiazin-4-one Moiety

Łukasz Popiołek

Chemical Science International Journal, Page 231-240
DOI: 10.9734/ACSJ/2015/16728

The reaction of hydrazides of carboxylic acids with aldehydes is an efficient synthetic method to produce N-substituted hydrazone derivatives. The resulting hydrazone compounds are considered as convenient intermediates and can be used to obtain new interesting heterocyclic systems e.g. 1,3-thiazolidin-4-one or 1,3-benzothiazin-4-one derivatives. In the present work such pathway was used for the synthesis of new 1,3-benzothiazin-4-one derivatives (16-30). New compounds were obtained by the cyclization reaction of N-substituted 4-(dimethylamino)benzhydrazides (1-15) with thiosalicylic acid. The spectral (IR, 1H NMR, 13C NMR) and elemental analysis confirmed the structure of synthesized compounds.

 

Open Access Original Research Article

Assessing the Quality of Rainwater from Different Roof Types in Kuntanase, Ghana

A. Adu Poku, N. Bakobie, S. J. Cobbina, A. B. Duwiejuah

Chemical Science International Journal, Page 183-191
DOI: 10.9734/ACSJ/2015/15883

Aims: The present study assessed the quality of rainwater harvested from three different roofing types namely aluminium, thatch and galvanised in Kuntanase, Ashanti Region, Ghana.

Study Design: A total of twenty one samples were collected from three different roof types (aluminium, thatch and galvanised) from the study area.

Place and Duration of Study: Triplicate samples were collected from each sampling site in the study area from March to April, 2014.

Methodology: Samples were collected and kept in ice chest (4°C) and conveyed to Kwame Nkrumah University of Science Technology laboratory for analysis of total hardness and coliforms. pH and electrical conductivity of rainwater were determined immediately after sampling in the field.

Results: EC and total hardness values obtained were within World Health Organization stipulated limits for potable water except pH. The present study obtained total coliform count that ranged from 4.0 ×105 to 4.4 ×107 cfu/100 ml with a general mean of 6.45 x 106±9.58 cfu/ 100 ml.

Conclusion: The study shows that microbial aerosols, debris and dirts and faecal waste are major pollutants of the rainwater harvested. The detection of total and faecal coliform from the harvested rainwater is evident that the rainwater is contaminated and has the potential of causing water-related disease burden if not treated before drinking.

 

Open Access Original Research Article

N-Monobenzoylation (acetylation, arylsulfonation), N-, C- di- and N-, C-, O- tribenzoylation of 5H(chloro, nitro)-2-methyl(ethyl)benzimidazoles

Khusnutdin M. Shakhidoyatov, Tozagul U. Dzhumatanova, Ubaydullo M. Yakubov, Azimjan A. Mamadrahimov, Gulsara E. Berdimbetova

Chemical Science International Journal, Page 192-204
DOI: 10.9734/ACSJ/2015/15935

The interaction of 2-methyl(ethyl)-5H(chloro, nitro)benzimidazoles with benzoyl (acetyl) chloride, and p-toluenesulfonyl chloride in the presence of triethylamine in tetrahydrofuran or chloroform was studied. It was found that the reaction proceeds in three stages with the formation of N-monobenzoyl (acetyl, p-toluenesulfonyl), N-, C-dibenzoyl- and N-, C-, O-tribenzoyl benzimidazoles depending on the ratio of reagents, the nature of the substituent in the aromatic ring, α-methylene group, and acid chlorides. It was revealed that in the case of acetyl, p-toluenesulfonyl chloride reaction is stopped at the first stage with formation of N-monoacetyl (p-toluenesulfonyl) derivatives. The method for HPLC analysis for separation, identification and determination of the ratio of obtained compounds was developed. It was found that 1-acetyl (benzoyl)-2-methylbenzimidazoles were decomposed at the standing. The crystalline form of 1-acetyl-2-methylbenzimidazole is decomposed to the 2-methylbenzimidazole: 25% (7 days), 50% (15 days), 100% (30 days) and decomposition of 1-benzoyl-2-methylbenzimidazole to the 2-methylbenzimidazole (50%) occurs within 2 months.

 

Open Access Original Research Article

Studies on the Production of Citric Acid by Rhizopus stolonifer

Ogbonnaya Nwokoro

Chemical Science International Journal, Page 205-212
DOI: 10.9734/ACSJ/2015/15860

A fermentation process was developed for citric acid production from orange peel waste by Rhizopus stolonifer. In a screening programme to select the best citric acid producing fungus, it was showed that after 3 days of incubation, the amount of citric acid in the screening medium varied depending on the isolate used. Rhizopus stolonifer produced the highest citric acid titre (5.8 g/L) and was therefore selected for fermentation studies. The addition of 3% and 4% (v/v) methanol into the isolation medium resulted in a citric acid yield of 7.8 g/L and 7.1 g/L respectively. This level corresponded to 135 and 122% respective increases in citric acid yield in comparison to the control medium that produced only 5.8 g/L. The basal medium was supplemented with different concentrations of lactose, maltose and sucrose. It was found that sucrose at 15% (w/v) concentration caused the best citric acid yield (33.7 g/L). Yields of citric acid generally increased with sugar concentrations and maximum production rates were achieved at 10–15% of sugar.

 

Open Access Original Research Article

Removal of Cr3+ and Mn2+ Ions from Aqueous Solution Using Immobilized Bio-Sorbent

S. A. Osemeahon

Chemical Science International Journal, Page 224-230
DOI: 10.9734/ACSJ/2015/13734

This research studied the removal of heavy metal ions from aqueous solution using a bio-sorbent. The bio-sorbent was prepared by entrapping or caging Moringa oleifera bark (IMOB), within a polymeric matrix of Calcium Alginate to produce immobilized bio-sorbent. The sorption efficiencies of heavy metals (Cr3+ and Mn2+ ions) were investigated using the IMOB biomass. The result obtained showed that the sorption efficiency of Cr3+ and Mn2+ by IMOB were 99.22% and 90.13% respectively. The sorption efficiency with respect to contact time, initial metal concentration, ionic strength and pH were investigated. The result obtained showed that the sorption capacity by IMOB decreases with increase in ionic strength, but it increases as the pH, contact time and initial metal concentration increases. The ability of IMOB to adsorb heavy metal ions as shown from the result portrays it as a potential cheaper method for waste water treatment.

 

Open Access Review Article

A Review on Synthesis and Spectral Properties of Quinazolines and Pyrimidines

Hamdan S. Al-Ebaisat

Chemical Science International Journal, Page 213-223
DOI: 10.9734/ACSJ/2015/16128

Heterocyclic compounds has become a significant role in human life due to the different uses of these compounds. This type of compounds found strong attention among chemists and interested by studying the methods of their synthesis and study their properties. Heterocyclic compounds used in different fields like medicine, pharmacy, agriculture and industry and widely credited for development of human life. Study of these compounds occupies a prominent place in the science of chemistry. Heterocyclic compounds as known it is contain two different types of atoms in their structure so it was great interest in the synthesis and study their chemical, physical characteristics and spectral characteristics. Heterocyclic chemistry comprises at least half of all organic chemistry research worldwide. In particular, heterocyclic structures form the basis of many pharmaceutical, agrochemical and veterinary products. Heterocycles make up an exceedingly important class of compounds. In fact more than half of all known organic compounds are heterocycles. Many natural drugs such as quinine, palavering, emetine, theophylline, atropine, procaine, codeine, morphine and reserving are heterocycles. Almost all the compounds we know as synthetic drugs such as diazepam, chlorpromazine, ionized, metronidazole, azidothymidine, barbiturates, antipyrine, captopril and methotrexate are also heterocycles. Some dyes, luminophores, pesticides and herbicides are also heterocyclic in nature. One of the main objectives of organic and medicinal chemistry is the design, synthesis and production of molecules having value as human therapeutic agents. There are numerous biologically active molecules with six-membered rings, containing two hetero atoms. The development of research on biological activity of quinazoline compounds started when the compound 2-methyl-1, 3-aryl-4-quinazoline derivative was synthesized. This compound has soporific and sedative action. Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring. pyrimidine has many properties in common with pyridine, as the number of nitrogen atoms in the ring increases the ring pi electrons become less energetic and electrophilic aromatic substitution gets more difficult while nucleophilic aromatic substitution gets easier. In this report has been explained different methods synthesis of these compounds and study their spectral properties. I hope to benefit chemists and who interested in studying this type of compounds.