Synthesis and Study the Mesomorphic Behaviour of New N- acetyl and Their Diazetine: Mono and Twin

Abstract

Synthesis ,characterization of new mono and twin compounds containing heterocyclic four member ring as, 1,3- diazetine by four steps. The first step; includes preparation of 2- amino thiazole derivatives [I]a-c via ring closure reaction between acetophenone derivatives with thiourea in I2, while the second step includes condensation reaction between 2-amino thaizole derivatives[I]a-c and p-methoxy benzaldehyde to produce Schiff bases[II]a-c. The third step includes neculophilic attach from imine group toacetyl chloride to give N- acetyl cross bonding[III]a-c.Finally ; the fourth step is completed by the reaction of N- acetyl derivatives with sodium azide (NaN3) to yield new 1,3-diazetines. The synthesized compounds were characterized byNMR and IR spectroscopy .The study of liquid crystalline behaviour was carried out using optical polarising microscopy (OPM) and some of them by differential scanning calorimetry (DSC) . All compounds were synthesized which showed liquid crystalline properties on heating.

Modification, Characterization of New Thiazolidinone and Oxazolidinone Derived from Levofloxacin and Evaluation of Anti-Oxidant

“…The levofloxacin drug was fused to new five-membered rings of oxazolidinone and thiazolidinone. Several novel derivatives were found by using the FTIR, 1 H-NMR, and 13 CNMR spectra. The antioxidant activity of compounds 3 through 10 was then assessed.…”

“…The FT-IR spectrum showed the appearance of ν(C=O) acid chloride and ketone at (1768) cm -1 and (1718) cm -1 . It showed ν(C=C) at (1590) cm -1 , FT-IR spectrum of this compound (2) indicates that (CO-Cl) at (1768) cm -1 was disappeared from the spectrum while the appearance of the asymmetric and symmetric stretching bands of (NH2) absorption bands at (3434) cm -1 asym., (3298) cm -1 sym., also the presence of a sharp band of ʋ (N-H) at (3280) cm -1 , ʋ (C-H) aromatic at (3080) cm -1 , ʋ (C-H) aliphatic at (2977, 2839) cm -1 and ʋ(C=O) at (1701, 1683) cm -1 ,1H-NMR and 13 C-NMR are shown in Table 4 and 5. Figure 2-5.…”

“…Physiochemical properties as shown in Table 1. [13,[20][21][22] A mixture of acid hydrazide (0.5 g, 0.0013 mmol) and various aromatic ketones [p-bromo Acetophenone, p-Chloro Acetophenone, p-amino Acetophenone] (0.0013 mol) in methanol (20 mL) and few drops of GAA was refluxed for 8 hours; the precipitate was filtered, washed with diethyl ether to give the final product. The physical properties are listed in Table 1.…”

“…The FT-IR spectra of compounds [3][4][5] shown disappearance of amine absorption bands of acid hydrazide, while appearance of new bands of azomethine (C=N) at (1639-1641) cm -1 , FTIR spectral data showed absorption at (C-H) aromatic bands at (3160-3043) cm -1 , ν (C=O) amide absorption bands at (1689-1658) cm -1 and (C=C) aromatic bands at (1575-1542) cm -1 spectrum. While the 1 H-NMR spectral data for compound [5] appeared doublet signal at δ= 1.22 ppm (3H, -CH3-CH, CH3 in oxazine ring); singlet signal at δ= 2.23 ppm (3H, -CH3-N-); triplet signal at δ= 2.50-3.11 ppm (2H,-N-CH2-CH2-N-, 2CH2 in piperazine ring); multiplet signal at δ= 4.38 ppm (1H, -O-CH2-CH-); singlet signal at δ= 4.94 ppm (1H, -NH2); while appeared multiplet signal at δ= 6.51-7.59 ppm (m, 5H, Ar-H); singlet signal at δ=8.92 ppm (1H, -CO-NH); at δ= 9.11 ppm (s, 1H, -N-CH=C(CO)2 and 13 C-NMR spectral data are listed in Table 5 and Figure The Thiazolidin-4-one derivative was synthesized by cyclization reaction of Schiff base [3][4][5] with thioglycolic acid in DMF as a solvent, as shown in Scheme (1), to produce compounds [9][10][11]. These compounds' FTIR spectra showed the disappearance of azomethine group absorption bands at range (1639-1641) cm -1 , show the bands of (C-S) thiazolidine ring absorption at range (655-713) cm -1 , while showed absorption band for (C-H) aromatic at (3037-3089) cm -1 , ν (CO-NH) at (1620-1680) cm -1 and ν (C=O) at (1703-1733) cm -1 for thiazolidine ring, and ν (C=C) at (1566-1602) cm -1 for aromatic bands.…”