2-[(3S)-1-Ethylpyrrolidin-3-yl]-2,2-diphenylacetamide in which one of the hydrogens at the 2-position of the ethyl group is substituted by a 2,3-dihydro-1-benzofuran-5-yl group. It is a selective antagonist for the M3 muscarinic acetylcholine receptor, which is primarily responsible for bladder muscle contractions, and is used as the hydrobromide salt in the management of urinary incontinence.