Washizuka, Ken-Ichi; Nagai, Keiko; Minakata, Satoshi; Ryu, Ilhyong; Komatsu, Mitsuo published their research in Tetrahedron Letters on December 10 ,1999. The article was titled 《Novel generation of azomethine imines from α-silyl nitrosamines by 1,4-silatropic shift and their cycloaddition》.Electric Literature of C6H8N2O2 The article contains the following contents:
The novel and facile generation of azomethine imines from α-silyl nitrosamines and their subsequent cycloaddition with dipolarophiles leading to a variety of pyrazoles is described. The key to the reaction is a 1,4-silatropic shift caused by strong affinity of the nitroso O atom toward the Si atom. Thus, α-silyl nitrosamines are treated with 1 equivalent of dipolarophile in refluxing PhMe for 1 h to give pyrazoles in good to excellent yields. The experimental part of the paper was very detailed, including the reaction process of Methyl 1-methyl-1H-pyrazole-4-carboxylate(cas: 5952-93-2Electric Literature of C6H8N2O2)
Methyl 1-methyl-1H-pyrazole-4-carboxylate(cas: 5952-93-2) belongs to pyrazoles. Pyrazoles and their related multiring analogs are common elements of a wide variety of bioactive compounds. These ring structures are rare in nature. A consequence of this is that they have previously been thought to be poor moieties to include in potential new drugs. Electric Literature of C6H8N2O2
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics