相关实验视频
Updated: Jul 2, 2025

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines
Published on: June 23, 2019
通过α-Halomethylsilanes作为掩盖甲基化试剂对Pyrazoles进行N1-选择性甲基化
1Department of Small Molecule Process Chemistry, Genentech, Inc., South San Francisco, California 94080, United States.
一种新方法使用掩盖甲基化试剂进行选择性N-甲基化. 这种方法为生产N-甲基火提供了高的区域选择性和良好的产量.
科学领域:
- 有机化学 有机化学
- 异环化学 异环化学
- 合成方法论 合成方法论
背景情况:
- 皮拉异循环是药物化学中的重要支架.
- 传统的N-甲基化方法往往缺乏区域选择性,导致异构体的混合.
- 开发选择性合成路径对于有效的药物发现和开发至关重要.
研究的目的:
- 开发一种高度选择性的N-甲基化方法,用于pyrazole异环.
- 为了利用新的,稳定的α-甲基西兰作为掩盖甲基化剂.
- 在各种pyrazole基质的N-甲基化中实现高N1/N2区域选择性.
主要方法:
- 采用绝缘体积大的α-甲基西兰作为掩盖甲基化试剂.
- 在优化的条件下,与这些试剂反应各种pyrazole基质.
- 使用化物源和水进行容易的原化,以产生N-甲基火.
主要成果:
- 获得了高的N-甲基化选择性对于pyrazole异环,N1/N2区域异构比从92:8到>99:1.
- 证明了硬质体积大的α-甲基西兰在提高对传统试剂的选择性方面的有效性.
- 获得的N-甲基pyrazoles在各种pyrazole基质中产生良好的产量.
结论:
- 开发的方法为Pyrazoles的N-甲基化提供了一个高度选择性和高效的途径.
- α-Halomethylsilanes作为有价值的掩盖甲基化试剂用于异环合成.
- 这种方法为获得特定的N-甲基化pyrazoles提供了一种实际的方法.
更多相关视频
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
10:42Preparation of N-2-alkoxyvinylsulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines
Published on: January 3, 2018
相关概念视频
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Phase II Reactions: Methylation Reactions
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
Nucleophilic Aromatic Substitution: Addition–Elimination (SNAr)
The reaction begins with an attack of the nucleophile on the carbon that holds the leaving group. This results in the delocalization of the π electrons over the ring carbons. The resonance interaction between...
Nucleophilic Aromatic Substitution: Elimination–Addition
Preparation and Reactions of Sulfides