Aluminium Chloride‐Mediated Synthesis of 1‐Chloro‐2,2,2‐Trifluoroethylidene‐Substituted Pyrrolidones

Abstract

An aluminium chloride-mediated cascade reaction between pyrrolidones and trifluoroacetic anhydride is reported. Functionally diverse 1-chloro-2,2,2-trifluoroethylidene-substituted pyrrolidones were obtained in moderate to high yields through electrophilic trifluoroacetylation, nucleophilic chlorination, and elimination. This procedure has a wide scope, good functional-group tolerance and the reaction conditions are amenable to scale up. Additionally the obtained 1-chloro-2,2,2-trifluoroethylidene products can be applied to further functionalization as trifluoromethyl-containing building blocks. Some of the title compounds showed fungicidal activity against cucumber downy mildew (CDM). . Reagents were received from commercial sources. Solvents were freshly dried and degassed according to the published procedures prior to use.

A Simple and Efficient Approach for the Synthesis of Aryl-3-(trifluoromethyl)-1H-1,2,4-triazol-5(4H)-one Derivatives

“…In continuation of our work on the synthesis of trifluoromethylated triazolone compounds [35][36][37][38][39][40] with potential biological activity, herein, we report an efficient, two-step, concise, non-catalytic direct method for the preparation of new and known fluorinated triazolone derivatives in excellent yields via reactions of aryl amidrazone derivatives with ethyl chloroformate followed by cyclization (Scheme 1f).…”

“…Continuing of our works to synthesis of trifluoromethylated triazolone compounds [36][37][38][39][40][41] with biological activity's potential, herein, we wish to report an efficient, concise, non-catalytic direct method for synthesis of new fluorinated triazolone derivatives via aryl amidrazone derivatives with ethyl chloroformate (ECF) in two steps with excellent yields.…”

Synthesis of 2-trifluoromethyl chromenes via double carbonyl–ene reaction

“…As part of our continuing research interest in synthetically important heterocyclic frameworks, we have recently developed various new methods for the synthesis of trifluoromethylated heterocyclic compounds using inexpensive and readily available trifluoromethylating reagents. [25][26][27][28][29][30] In continuation of our endeavors to this research, herein we describe a catalyst-free approach for the synthesis of 2-trifluoromethyl chromenes from reaction of o-isopropenylphenols with trifluoroacetic anhydride (Scheme 1e) via sequential trifluoroacetylation and double carbonyl-ene reaction, 31 followed by elimination reaction.…”

Preparation of Chromeno[b]quinoline Derivatives and Their Application for Lipid Droplets Markers

“…(v) Nucleophilic attack: nucleophilic attack of the lone pair of electrons on the nitrogen atom causes intramolecular aromatization, and then, the intramolecular protons transfer to a configuration with a better degree of conjugation. 16 (vi) The catalyst leaves: with the departure of the leaving group, 17 the chromo[b]quinoline-conjugated heterocyclic dye 3a is finally obtained.…”