Synthesis and thermal behaviour of new benzo-1,2-thiazine long-chain aryl-piperazine derivatives

Abstract

A series of potential biologically active 2-[3-(4-phenyl-1-piperazinyl)propyl]-3-(4-substituted-benzoyl)-4-hydroxy-2H-1,2-benzothiazine 1,1-dioxides was synthesized in a straightforward manner by condensation of respective 3-substituted-4-hydroxy-1,2-benzothiazine 1, 1-dioxides with 1-(1-chloropropyl)-4-phenylpiperazine. The structures of all of the newly formed compounds were identified by elemental analysis, FTIR and 1 H NMR. The synthesized compounds were subjected to preliminary evaluation using differential scanning calorimetry (DSC) to determine the existence of multiple crystal forms. The DSC scans for all compounds show more than one endothermic effect, which might suggest dynamic proton transfer between two or three possible tautomeric forms: O-keto/O-enol, O-enol/O-keto and O-keto/O-keto/CH 2 in crystals 2-[3-(4-phenyl-1-piperazinyl)propyl]-3-(4-substituted-benzoyl)-4-hydroxy-2H-1,2-benzothiazine 1,1-dioxides.

Synthesis, COX-1/2 inhibition and antioxidant activities of new oxicam analogues designed as potential chemopreventive agents

“…Synthesis and experimental data for the 1,1-dioxo-2-[2-oxo-2-(p-substituted-phenyl)ethyl]-1,2-benzothiazol-3-one 3a-d compounds were previously reported (Krzyżak et al, 2014;Szczęśniak-Sięga et al, 2014;Yoshimura et al, 2015).…”

“…Synthesis and experimental data of compounds 4a, 4b and 4d were previously reported (Krzyżak et al, 2014;Szczęśniak-Sięga et al, 2014).…”

“…1,1-dioxo-3-(p-methylbenzoyl)-4-hydroxy-2H-1,2-benzothiazine 4c 85% yield, mp 232-233ºC; 1 H NMR (300 MHz (Lopez et al, 2010;Krzyżak et al, 2014;Maniewska et al, 2014;Paudel et al, 2016).…”

Structural elucidation of thermolysis products of methyl N-methyl-N-nitrosoanthranilate

“…When it comes to their thermal stability, they are deemed stable at room temperature, while they are being decomposed at temperatures above 200 °C with liberation of NO. [23][24][25][26] Depending on the structure of the initial molecule and thermolysis conditions, thermolysate may contain compounds that are the results of decomposition of the initial material and/or compounds formed by the decomposition or recombination of fragments formed from the initial compounds. [13][14][15][16][17][18] Methyl N-methylanthranilate is a part of our everyday diet as it naturally occurs in various fruits and plants and is used as a food flavor.…”

Synthesis and DSC study a new pyridinedicarboximide diones derivatives, obtained under various conditions

“…It is combined with other techniques, such as FTIR, NMR, and XRD [17][18][19][20][21][22][23]. The main concept of this work is to determine the thermal properties of three derivatives of 3,4-pyridinedicarboximides (slightly differ in molecular structure).…”