Flood reaction

What is Flood reaction?

In 1933, Flood reported a chemical reaction that involves the synthesis of trialkylsilyl halide, known as the Flood reaction, which is achieved by treating a mixture of di-trialkylsilyl oxide and concentrated sulfuric acid H2SO4 with sodium halide NaX or ammonium halide NH4X.

Flood reaction - general reaction scheme
Flood reaction

The resulting trialkylsilyl halide can be isolated and purified via distillation after extraction with petroleum ether. Further studies revealed that di-trimethylsilyl oxide mixed with concentrated sulfuric acid H2SO4 produces trimethylsilyl sulfate, which can be converted into trimethylsilyl halide upon reaction with ammonium halide.

The reaction has been improved by extracting the reaction mixture with pentane continuously, leading to higher yield and purity of trialkylsilyl halide, and by the addition of ammonium bisulfate (NH4)HSO4 to the reaction mixture.


Preparation of Triethylsilicon Halides
E. A. Flood
Journal of the American Chemical Society 1933 55 (4), 1735-1736
DOI: 10.1021/ja01331a504