Oxitropium bromide

Oxitropium bromide is an anticholinergic used as a bronchodilator for the treatment of asthma and chronic obstructive pulmonary disease.
It was patented in 1966 and approved for medical use in 1983.
It is a thermosalient material.

Synthesis

Two successive alkylation reactions convert a natural product, norscopolamine, into oxitropium bromide. The first, with bromoethane, gives an N-ethyl intermediate, which is treated with bromomethane.