tris(2-perfluorohexylethyl) tin azide: A new reagent for preparation of 5-substituted tetrazoles from nitriles with purification by fluorous organic liquid-liquid extraction

The synthesis of a new fluorous tin azide, (C6F13CH2CH2)(3)SnN3, is reporte d and this reagent is used to make tetrazoles in both traditional and phase -switching modes. In the traditional mode, the tin azide is reacted with ni triles followed by HCl cleavage to provide the tetrazoles and the fluorous tin chloride (which can be reconverted into the tin azide). In the switchin g mode, the initial tin tetrazole is purified by fluorous/organic liquid-li quid extraction prior to destannylation. This provides pure products even i n incomplete reactions or with impure starting materials, but it only works for smaller nitriles. (C) 1999 Elsevier Science Ltd. All rights reserved.