Synthesis and Identification of Heterocyclic Compounds (Oxazepine, Tetrazole) Derived from Benzidine as Photostabilizing for Poly vinyl chloride

Abstract

This research describes preparation of new four compounds (A2-A5) having 1,3-oxazepine and Tetrazole rings. The first step involves reaction of benzidine (A1) with aromatic aldehyde (cinnamaldehyde) in ethanol as a solvent in the presence of acid as catalyst to yield the Schiff base (A2), Schiff base (A2) was condensed with maleic anhydride and phthalic anhydride in dry benzene to give a seven-membered heterocyclic ring derivative (A3, A4), In addition, we synthesis novel tetrazole derivative (A5) from the reaction of Schiff base (A2) with sodium azide in tetrahydrofuran. The structure of synthesized compounds were identified by spectral methods [FTIR, ¹H-NMR, and ¹³C-NMR] and measurement physical properties. The photo stabilization of poly (vinyl chloride) films by compounds (A1-A5) was studied. The Photostabilization activities of these compounds were determined by monitoring the carbonyl and hydroxyl indexes values with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were studied by using tetrahydrofuran as a solvent. The influence of concentrations additives (range 0.1-0.5wt) on the rate of photodegradation and Photostabilization course was studied. Therefore, we found that was an increase Photostabilization rates with increasing concentrations of additives. In addition, Studying the effect of film thickness and the results showed that an increase in film thickness would reduce the rate of photolysis. The results indicated that Photostabilisation proportion of plastic in the presence of additives follow the trend: (PVC blank) > PVC+A1> PVC+A2 > PVC+A5> PVC+A4> PVC+A3. According to the results obtained, it proposed mechanisms depending on the structure of the additive.

Synthesis and characterization Some of heterocyclic compounds from Nitrogen derivative

“…Azo-Schiff bases (S 1 -S 3 ) were synthesized by condensation of the equimolar quantity of primary aromatic amines (4-amino phenol, 3-nitro aniline, 4-methal aniline) with azo acetophenone derivative (A). Apericyclic reaction (Nief, 2018) is one that occurs by a concerted process through a cyclic transition state. The word concerted means that all bonding changes occure simultaneously; no intermediates are involved (Khidir et al, 2018).…”

Diamine Derivatives as Photostabilizers for Thermoplasticized Poly(Vinyl Chloride) [I]

“…The absorption،spectra of poly (vinyl chloride)1films1were recorded in1the range of (4000-400) cm -1 . The position of carbonyl absorption was specified at 1730 cm -1 (22,23). The1progresses of photodegradation through different irradiation times were1followed1by noting changes in carbonyl peaks.1Then carbonyl (I CO ) indices were calculated by comparison of the، FTIR absorption1 peak، at 1722 cm -1 with1reference peak at 1328 cm -1 ,1respectively.1This method is called band index method1 which includes1as1equation (1):…”

“…The actual1 absorbance 1difference1between1the absorbance of the highest1peak and the baseline (A1Top beak-base1line) was calculated using،1the baseline1method (22,24).…”

“…As a consequence، of photo-oxidation1 degradation1 in PVC is the reduction1of the average molecular1 weight1 of the polymer1 which1 is a result1 of photolytic1 chain1scission. The changes in the molecular، weight ̅ , of PVC films، with and without additive after irradiation with light1 intensity1 of (6.4 x 10 -7 Ein.dm -3 .s -1 ) were monitored by1 viscosity1 measurement using equation (2) and THF as solvent at 25 ο C.The values of constant in this equation(K=1.5×10 -2 g/ml, α'=0.77),when PVC films (with or without additive) were exposed to irradiation the intrinsic، viscosity and viscosity، average molecular weight، decrease with the increase of irradiation time (22,23). Figure (13) shows the relative changes in the viscosity averagee molecular weight ( ̅ ) with irradiation1 time for PVC without and with 0.51% of additives, this figure indicates a1rapid decrease in ( ̅ ) initially then it1slows1down1suggesting1 that the1initial rapid drop1in1 ( ̅ )1is due1to scission of bonds1 at various weak links، that distributed along the polymer chain.…”

Synthesis, identification, and cytotoxicity effect of Oxazapine scaffolding

“…It had prepared by the condensation of Schiff bases with carboxylic acid anhydride (3,4). Their chemical structure has a distinctive feature in pharmacological chemotherapy drugs: antimicrobial (5), anti-cancer and anti-tuberculosis (6,7), anti-inflammatory (8), antioxidant (9), antifungal (10), and antibacterial. As auxiliary agents and in the manufacture of dyes as coloring materials, inhibitors of metal corrosion (11), and has a varied biological activity, its effectiveness used as an anticoagulant (12), treatment of mental disorders (13,14), anti-tumor (15), (16).…”