N-Methylation at the pyrazole ring by sequential treatment of 5-tributylstannyl-4-trifluoromethylpyrazole with LDA and iodomethane regioselectively provided the title compound in high yield. The addition reaction of 5-lithiated-4-trifluoromethylpyrazole with a wide range of electrophiles allowed easy and high-yielding introduction of substituents on position 5.

中文翻译：

---

1-甲基-5-三丁基锡烷基-4-三氟甲基吡唑的合成与反应

通过用LDA和碘甲烷顺序选择性处理5-三丁基锡烷基-4-三氟甲基吡唑在吡唑环上进行N-甲基化，可以高收率选择性地提供标题化合物。5-锂化-4-三氟甲基吡唑与各种亲电试剂的加成反应使位置5上的取代基容易且高产地引入。