3159-07-7Relevant articles and documents
The behaviour of some thioxanthene and thianthrene derivatives with hydrazoic acid
Palazzo,Giannola,Caronna
, p. 839 - 841 (1974)
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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.
Reductive Condensation of a Nitro Group with Carboxylic Acids Promoted by Phosphorus(III) Compounds: A Short Route to 5 H -Dibenzo[ b, e ][1,4]diazepin-11(10 H)-ones
Tryniszewski, Micha?,Bujok, Robert,Gańczarczyk, Roman,Wróbel, Zbigniew
, p. 3086 - 3094 (2020/08/10)
Tributyl- or triphenylphosphine promotes a one-pot, three-step method for the synthesis of differently substituted dibenzodiazepinones from N -aryl-2-nitroanilines. Pyridine analogues and the corresponding thiazepinones can also be formed using this method. The process involves deoxygenation of the nitro group, then formation of an iminophosphorane intermediate and its intramolecular condensation with a carboxyl group placed in the N -aryl group. The role of the carboxyl group in the formation of the iminophosphorane and the mode of cyclization are discussed.
Generation of Aryl Radicals from Aryl Halides: Rongalite-Promoted Transition-Metal-Free Arylation
Yu, Fazhi,Mao, Runyu,Yu, Mingcheng,Gu, Xianfeng,Wang, Yonghui
supporting information, p. 9946 - 9956 (2019/09/04)
A new and practical method for the generation of aryl radicals from aryl halides is reported. Rongalite as a novel precursor of super electron donors was used to initiate a series of electron-catalyzed reactions under mild conditions. These transition-metal-free radical chain reactions enable the efficient formation of C-C, C-S, and C-P bonds through homolytic aromatic substitution or SRN1 reactions. Moreover, the synthesis of antipsychotic drug Quetiapine was performed on gram scale through the described method. This protocol demonstrated its potential as a promising arylation method in organic synthesis.