26177-44-6Relevant articles and documents
Preparation method of intermediate p-bromobenzylamine hydrochloride for synthesizing protein degradation agent 1
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Paragraph 0018; 0020-0024; 0026-0029; 0031-0034; 0036-0038, (2021/06/02)
The invention discloses a preparation method of an intermediate p-bromobenzylamine hydrochloride for synthesizing a protein degradation agent 1, which comprises the following steps: sequentially adding a certain amount of p-bromobenzyl bromide, sodium diformylamide and an ether inert solvent, conducting reacting for 10-15 hours at a certain temperature, cooling the reaction system to room temperature, and conducting filtering to obtain filtrate; concentrating the filtrate under reduced pressure to remove the solvent to obtain a residue, sequentially adding a certain amount of ethanol and concentrated hydrochloric acid into the residue, conducting reacting for 15-20 hours at a certain temperature, and cooling a formed reaction system to room temperature; and then adding a certain amount of ethyl acetate for crystallization, and conducting filtering and drying to obtain the p-bromobenzylamine hydrochloride. According to the synthesis method of the p-bromobenzylamine hydrochloride, dangerous chemicals sodium azide and hydrazine hydrate used in preparation of the p-bromobenzylamine hydrochloride reported in existing literatures are avoided, meanwhile, the three wastes are few, the yield is high, and the synthesis method has the advantages of being easy to operate, high in safety, good in product quality, low in cost and the like and is convenient for large-scale production.
Phosphine-Free Manganese Catalyst Enables Selective Transfer Hydrogenation of Nitriles to Primary and Secondary Amines Using Ammonia-Borane
Sarkar, Koushik,Das, Kuhali,Kundu, Abhishek,Adhikari, Debashis,Maji, Biplab
, p. 2786 - 2794 (2021/03/03)
Herein we report the synthesis of primary and secondary amines by nitrile hydrogenation, employing a borrowing hydrogenation strategy. A class of phosphine-free manganese(I) complexes bearing sulfur side arms catalyzed the reaction under mild reaction conditions, where ammonia-borane is used as the source of hydrogen. The synthetic protocol is chemodivergent, as the final product is either primary or secondary amine, which can be controlled by changing the catalyst structure and the polarity of the reaction medium. The significant advantage of this method is that the protocol operates without externally added base or other additives as well as obviates the use of high-pressure dihydrogen gas required for other nitrile hydrogenation reactions. Utilizing this method, a wide variety of primary and symmetric and asymmetric secondary amines were synthesized in high yields. A mechanistic study involving kinetic experiments and high-level DFT computations revealed that both outer-sphere dehydrogenation and inner-sphere hydrogenation were predominantly operative in the catalytic cycle.
A cobalt phosphide catalyst for the hydrogenation of nitriles
Jitsukawa, Koichiro,Mitsudome, Takato,Mizugaki, Tomoo,Nakata, Ayako,Sheng, Min,Yamasaki, Jun
, p. 6682 - 6689 (2020/08/24)
The study of metal phosphide catalysts for organic synthesis is rare. We present, for the first time, a well-defined nano-cobalt phosphide (nano-Co2P) that can serve as a new class of catalysts for the hydrogenation of nitriles to primary amines. While earth-abundant metal catalysts for nitrile hydrogenation generally suffer from air-instability (pyrophoricity), low activity and the need for harsh reaction conditions, nano-Co2P shows both air-stability and remarkably high activity for the hydrogenation of valeronitrile with an excellent turnover number exceeding 58000, which is over 20- to 500-fold greater than that of those previously reported. Moreover, nano-Co2P efficiently promotes the hydrogenation of a wide range of nitriles, which include di- and tetra-nitriles, to the corresponding primary amines even under just 1 bar of H2 pressure, far milder than the conventional reaction conditions. Detailed spectroscopic studies reveal that the high performance of nano-Co2P is attributed to its air-stable metallic nature and the increase of the d-electron density of Co near the Fermi level by the phosphidation of Co, which thus leads to the accelerated activation of both nitrile and H2. Such a phosphidation provides a promising method for the design of an advanced catalyst with high activity and stability in highly efficient and environmentally benign hydrogenations. This journal is
