In this work, an important sugar alkynyl ether has been synthesized in two subsequent steps starting from commercially available D-galactose (3). This kind of compounds is highly significant in the synthesis of biologically active molecules such as 1,2,3-triazole and isoxazoles. In the first step, galactose (3) was reacted with acetone in the presence of anhydrous copper (II) sulfate to produce 1,2:3,4-di-O-isopropylidene-α-D-galactose (4) in good yield. The latter was reacted with excess of 3-bromoprop-1-yne in DMF in the presence of NaOH pellets to afford the target molecule 5 in a very good yield. The temperature of this step is crucial in determining the reaction yield. The exact structure of compound 5 is identified using NMR technique and DFT calculations.
In this paper, some chalcone derivatives (C1, C2) were synthesized based on the reaction of equal amount of substituted acetophenone and substituted banzaldehyde in basic medium. Oxazine and thiazine derivatives were prepared from the reaction of chalcones (C1-C2) with urea and thiourea respectively in a basic medium. Pyrazole derivatives were prepared based on the reaction of chalcones with hydrazine mono hydrate or phenyl hydrazine in the presence of glacial acetic acid as a catalyst. The new synthesized compounds were identified using various physical techniques like1 H-NMR and FT-IR spectra.
Within this paper, we developed a new series of organic chromophores based on triphenyleamine (TPA) (AL1, AL-2, AL-11 and AL-22) by engineering the structure of the electron donor (D) unit via replacing a phenyle ring or inserting thiophene as a π-linkage. For the sake of scrutinizing the impact of the TPA donating ability and the spacer upon the photovoltaic, absorptional, energetic, and geometrical characteristic of these sensitizers, density functional theory (DFT) and time-dependent DFT (TD-DFT) have been utilized. According to structural characteristics, incorporating the acceptor, π-bridge and TPA does not result in a perfect coplanar conformation in AL-22. We computed EHOMO, ELUMO and bandgap (Eg) energies by performing frequency a
... Show MoreThe voice had a special place in the writting of the Andalusian poet (Ibn al-Abar ) , which aroused my attention because of the sonic capacity of the lettering inside the poetic at Ibn al-Abar poems . So Istudied the qualities of the lettering , structures and their exits . Scientists have not been able to determine the musical from the nonmusical sound , but we find the innate ability of Ibn al-Abar , which was able to determine this by using the lettering the right places and to revival the life to reflect the moments of his life , therefore came votes to express his purposes of praise and pride Etc. The poet Ibn al-Abar could exploit the lettering features in the effect of bilateral – static and moving and its ability to e
... Show MoreDespite efforts to contain and manage the SARS-CoV-2 outbreak which was declared a public health emergency of international concern in January 2020 by the World Health Organization (WHO), the COVID-19 pandemic still remains a major global challenge. Patients who display the classical symptoms of the infection are easily identified, tested, isolated and monitored. However, many cases of infected asymptomatic patients have been documented. These patients are not easily identified even though many evidences suggest that they can spread the virus to others. How and why these COVID-19 asymptomatic presentations occur remain unclear. The many theories and views are conjectural, and supporting evidences are still needed. In this review, we
... Show Moreللشعب العربي ولع عميق و ميل شديد إلى الأسفار و الإنتقال من بلد إلى آخر ، لا تثنيهم عن ذلك صحارى واسعة و لابحار شاسعة أو مشاق عنيفة . و قد توارثوا هذا الميل منذ زمن قديم فأوغلوا في قارة آسيا و أفريقيا و أوربا وغيرها . و شقت سفنهم الخليج العربي و المحيط الهندي و البحر المتوسط و بحار اخرى . و لعل هذا الميل إلى الأسفار و الولع بالاغتراب قد عبًر عن نفسه بصورة أدبية في قصص السندباد و بصورة فعلية برحلة إبن جبير و رحلة إبن
... Show MoreArabic prose poem and the antithesis of contrast: poetry _ prose and West _ East