257-15-8Relevant academic research and scientific papers
Gas-phase cyclisation reactions of 1-(2-arylthiophenyl)alkaniminyl and 2-(aryliminomethyl)thiophenoxyl radicals
Creed,Leardini,McNab,Nanni,Nicolson,Reed
, p. 1079 - 1085 (2001)
Flash vacuum pyrolysis (FVP) of the oxime ethers 12-14 and of the sulfides 18-20 at 650°C (10-2-10-3 Torr) gave products derived from the corresponding iminyl and thiophenoxyl radicals. In all cases, benz[d]isothiazoles (e.g., 26) are formed as major products via SHi mechanisms though the yields are greatest with the iminyl precursors. Alternative pathways observed from the thiophenoxyls in specific cases include the formation of the anilinobenzothiophene 36 and of dibenzothiophene 23, via an SHi process and a spirodienyl rearrangement, respectively. There is no evidence for signicant interconversion of the iminyl and thiophenoxyl species.
Diversity in Heterocycle Synthesis Using α-Iminocarboxylic Acids: Decarboxylation Dichotomy
Laha, Joydev K.,Hunjan, Mandeep Kaur
, p. 2315 - 2323 (2022/02/07)
Despite the structural similarity with imines, α-iminocarboxylic acids have seldom been used in heterocycles synthesis. The reactions of ortho-substituted anilines and arylglyoxylic acids in DMSO at 40 °C gave various benzo-fused five- to six-membered N-heterocycles in good to excellent yields. The reaction proceeds via intramolecular Michael addition of α-iminocarboxylic acids, generated in situ, with an ortho-substituted nucleophile, yielding an isolable unprecedented tetrahedral carboxylic acids, which upon decarboxylation without any aid of additional reagents forms the N-heterocycles. DMSO is crucial in this reaction, perhaps because of improved solubility and the ease of decarboxylation of these tetrahedral carboxylic acids. However, a copper-catalyzed reaction of ortho-substituted anilines and 2-bromoarylglyoxylic acids gave a dibenzo-fused seven-membered N-heterocycle under a basic reaction condition. Unlike intramolecular cyclization with α-iminocarboxylic acids in the first case, α-iminocarboxylic acid undergoes a competitive decarboxylation under the copper-catalyzed conditions, which upon subsequent heteroarylation form the heterocycles. Taken together, the study described herein represents two different modes of decarboxylation observed with α-iminocarboxylic acids, leading to the synthesis of divergent heterocycles and pharmaceuticals, which remained unexplored previously.
A study of photodegradation of quetiapine by the use of LC-MS/MS method
Skibinski, Robert
experimental part, p. 232 - 240 (2012/04/10)
Photodegradation of quetiapine under UVC irradiation in methanol solution was investigated and structural elucidation of its photodegradation products was performed with the use of the reversed phase UHPLC system coupled with accurate mass hybrid ESI-Q-TO
New method for the preparation of dibenzo[b,f][1,4]thiazepines
Fujii, Takayoshi,Hao, Wei,Yoshimura, Toshiaki
, p. 246 - 250 (2007/10/03)
The S-amination of 9H-thioxanthen-9-ol (2a) and 9-substituted derivatives 2b-e (Me (b), Et (c), iPr (d), Ph (e)) with O- mesitylenesulfonylhydroxylamine (MSH) was carried out. The expected product, 10-amino-9-hydroxy-9-isopropyl-9H-thioxanthenium mesitylenesulfonate (3d), was obtained in 78% yield from the corresponding thioxanthen-9-ol 2d. However, in the case of 2a-c and 2e the reaction led instead to dibenzo[b, f][1,4]thiazepines 6a-c and 6e in moderate yields.
