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Wellbores are destabilized by the immersion of a formation in drilling fluid during deep well drilling. To address this issue, in the present study, trimethylolethane triallyl ether (TMETE), 2‐acrylamide‐2‐methylpropanesulfonic acid (AMPS), acrylamide, and N‐vinylpyrrolidone undergo free radical copolymerization to produce a PTAAN filter loss reducer. The Box–Behnken response surface method is used to optimize the synthesis of PTAAN; the optimal conditions are 1 wt% TMETE and 0.1111 wt% initiator at 60°C. Fourier transform infrared spectroscopy, transmission electron microscopy, and thermogravimetric analysis are used to characterize the composition, micromorphology, and thermal stability of the PTAAN product, respectively. The synthesized product is resistant to high temperatures and salt under the optimal synthesis conditions. It has an API filtration loss of 8.2 mL for freshwater‐based mud, an API filtration loss of 13.8 mL for 20% by weight brine mud after aging at 220°C, and an API filtration loss of 29.5 mL at 150°C under high temperatures and pressures. Incorporating PTAAN into the base slurry prevents clay particle agglomeration at elevated temperatures and high mineralization, resulting in a broader clay particle size distribution and ultimately leading to the formation of a thin and compact filter cake. [ABSTRACT FROM AUTHOR]

A DABCO‐promoted bicyclization/rearrangement reaction has been developed for the synthesis of tetrasubstituted furans from 1,4‐enediones at room temperature. This transformation involves aza‐Michael addition, intramolecular bicyclization, and rearrangement processes. In addition, the 4‐ureidofuran‐3‐carboxylate ester products can further be converted to furo[3,4‐d]pyrimidine‐2,4‐diones through intramolecular substitution cyclization under heating conditions. [ABSTRACT FROM AUTHOR]

Here we report the preparation of primary α‐ketoamides via a highly efficient molecular iodine‐mediated oxidative amidation of aryl methyl ketones with ammonium carbamodithioate. A self‐sequenced iodination/nucleophilic substitution/Kornblum oxidation/amidation mechanism was proposed. In this mechanism, α‐thiocyanatoacetophenone is the key intermediate. [ABSTRACT FROM AUTHOR]

A molecular iodine mediated condensation–cyclization reaction for the synthesis of 4‐aryl‐NH‐1,2,3‐triazoles has been developed from readily available α‐azido acetophenones and p‐toluenesulfonyl hydrazide. This reaction provides a metal‐free strategy for the sequential formation of C–N and N–N bonds in mild condition. [ABSTRACT FROM AUTHOR]

Although 2-imino-1 H-imidazol-5(2 H)-ones have important biological activities in metabolism, their synthesis has rarely been investigated. Quinoxalines as 'privileged scaffolds' in medicinal chemistry have been extensively investigated, but the development of novel and efficient synthetic methods remains very attractive. Herein, we have developed two copper-catalyzed domino reactions for the synthesis of 2-imino-1 H-imidazol-5(2 H)-ones and quinoxalines involving CC bond-cleavage with a 1,3-dicarbonyl unit as a leaving group. The domino sequence for the synthesis of 2-imino-1 H-imidazol-5(2 H)-ones includes aza-Michael addition, intramolecular cyclization, CC bond-cleavage, 1,2-rearrangement, and aerobic dehydrogenation reaction, whereas the domino sequence for the synthesis of quinoxalines includes aza-Michael addition, intramolecular cyclization, elimination reaction, and CC bond-cleavage reaction. The two domino reactions have significant advantages including high efficiency, mild reaction conditions, and high tolerance of various functional groups. [ABSTRACT FROM AUTHOR]

The reaction tolerates various aryl substituted α-bromo ketones, but no heterocyclic or alkyl substituted α-bromo ketones. [ABSTRACT FROM AUTHOR]

The efficient title reaction of ethoxycarbonyl, benzoyl or cyano substituted aryl or alkylketones with trans-β-nitrostyrenes and acetylene dicarboxylates provides polysubstituted phthalic acid derivatives in high yields. [ABSTRACT FROM AUTHOR]

A variety of 2-hydroxydihydrofuran derivatives are synthesized under mild reaction conditions by a domino reaction of readily available 1,4-enediones with phenacyl pyridinium halides. [ABSTRACT FROM AUTHOR]

A diagram of the access to polyfunctional pyrazoles by highly efficient regioselective multicomponent reaction is presented.

Intermediate formation of α-diazoketones (II) from glyoxal monohydrates (I) and tosylhydrazine is applied in the one-pot synthesis of 3-acylpyrazoles (IV) and (VI) as well as benzo[f]indazolediones (VIII) or chromeno[3,4-c]pyrazolones (XI). [ABSTRACT FROM AUTHOR]

Application of 1,4-benzoquinone, juglone or 1,4-anthracenedione do not yield the corresponding products. [ABSTRACT FROM AUTHOR]

This method is also applicable to a one-pot sequence starting from methyl ketones. [ABSTRACT FROM AUTHOR]

A novel copper-catalyzed synthesis of pyridopyrimidinones from 1,4-enediones and 2-amino-heterocycles is developed. [ABSTRACT FROM AUTHOR]