The invention discloses a series of difluoroketone mono. di- and tri-peptide derivatives of the formula la, Ib and Ic:-
and salts thereof where appropriate, and wherein the radicals are defined hereafter in the specification. The derivatives are useful in inhibiting the action of human leukocyte elastase. There are also disclosed methods and intermediates for the manufacture of, and pharmaceutical compositions comprising, the said derivatives.
The invention relates to selected difluoro compounds of formulae la, 1b and Ic (set out hereinafter) which are useful as inhibitors of human leukocyte elastase.