Abstract An efficient and convenient synthesis of 2‐substituted benzimidazoles catalyzed by magnetic Fe 3 O 4 supported by modified bentonite (MB) was developed. Herein, a separable, magnetic catalyst Fe 3 O 4 /MB was successfully prepared on the basis of exploring Fe 3 O 4 synthesis by co‐precipitation method. Fe 3 O 4 was obtained in 96.09 % yield using sweet orange oil as a reducing and protecting agent. The result showed that the sweet orange oil played a crucial role in the preparation of Fe 3 O 4 . Fe 3 O 4 and Fe 3 O 4 /MB were characterized by powder XRD, SEM, EDX, XPS and BET, and were further applied to catalyze the synthesis of 2‐substituted benzimidazoles. The applicability of the substrate was investigated on the basis of optimizing the reaction conditions. As a consequence, 2‐substituted benzimidazoles were obtained in 37.01–91.68 % yield. It suggested that Fe 3 O 4 /MB was an environmentally friendly and low‐cost catalyst possessing good catalytic activity, broader substrate adaptability and excellent recyclability. It is a promising catalyst in industrial production.
Herein, we report a synthetic route for an EGFR inhibitor, 2-(5-fluoro-2-hydroxyphenyl)-2-(1-oxoisoindolin-2-yl) acetic acid (EAI045), using a three-step approach. This short and efficient route is the first report of a scalable process for EAI045, which employs a convergent three-component coupling strategy as the key step, producing EAI045 in good yield on kilogram scale.
Abstract An efficient and convenient palladium-catalyzed reductive system by employing sodium hydride as the hydrogen donor and acetic anhydride as an activator has been developed for transfer hydrogenation and acetylation of a wide range of N-heteroarenes including quinoline, phthalazine, quinoxaline, phenazine, phenanthridine, and indole. Moreover, acridine substrates could be directly reduced without the use of acetic anhydride. This protocol provides a simple method for the preparation of various saturated N-heterocycles.
An amine and bis(phenylsulfonyl)methane co-catalyzed hydrogen-deuterium exchange (HDE) method via a Michael-retro-Michael pathway for site-selective introduction of deuterium at the α-position of enals using D2O as a deuterium source has been achieved. The mild, operationally simple protocol allows for high yielding and high level deuterium incorporation (up to 99%) for structurally diverse aromatic-derived enals and dienals.
A convenient and atom-economical procedure for the thermo-promoted reactions of anthranil with different substrates was developed. The catalyst-free process affords various useful building blocks with good to moderate yields. This chemistry enables several step- and cost-effective approaches for biologically interesting molecules and provides an efficient platform for the investigation of untapped reactions at high temperature.
An oxidant-free and highly efficient synthesis of phenolic quinazolin-4(3H)-ones was achieved by simply stirring a mixture of 2-aminobenzamides, sulfonyl azides, and terminal alkynes. The intermediate N-sulfonylketenimine underwent two nucleophilic additions and the sulfonyl group eliminated through the power of aromatization. The natural product 2-(4-hydroxybenzyl)quinazolin-4(3H)-one can be synthesized on a large scale under mild conditions with this method.
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