Abstract

Reactions of 3-tert-butyl-8-methylpyrazolo[5,1-c][1,2,4]triazine with lithium phenyldimethylsilanide and triphenylsilanide in THF media at −85 to −60 °C led to the formation of the silicon C(4)-addition products in high yields. Aromatic 3-tert-butyl-8-methyl-4-(triphenylsilyl)pyrazolo[5,1-c][1,2,4]triazine has been synthesized by oxidation of the corresponding 1,4-dihydro derivative using NBS/Et₃N in pentane at −30 to −15 °C. Preferential N(1)-nucleophilic additions of silanides were observed for the sterically hindered 3,4-di-R-8-methylpyrazolo[5,1-c][1,2,4]triazines (R = t-Bu, Ph₃Si). Novel C–Si derivatives of 1,2,4-triazines, as well as some other isolated compounds were characterized by IR, ¹H, ¹³C, ²⁹Si NMR, HRMS data and X-ray crystallography.

摘要

3-叔丁基-8-甲基吡唑并[5,1- c ] [1,2,4]三嗪与苯基二甲基硅烷锂和三苯基硅烷在THF介质中在-85至-60°C下反应导致形成硅C （4）增产高产。芳族3-叔丁基-8-甲基-4-（三苯基甲硅烷基）吡唑并[5,1- c ] [1,2,4]三嗪是通过使用NBS / Et氧化相应的1,4-二氢衍生物而合成的₃ N在-30至-15°C下的戊烷中。对于空间受阻的3,4-di-R - 8-甲基吡唑并[5,1- c ] [1,2,4]三嗪（R =  t -Bu，Ph，N，1）的N（1）亲核加成观察到₃Si）。通过IR，¹ H，¹³ C，²⁹ Si NMR，HRMS数据和X射线晶体学对1,2,4-三嗪的新型C-Si衍生物以及一些其他分离的化合物进行了表征。