Carbamic acid,[(1S)-2-[[(1S,2R)-1-[(3,5-difluorophenyl)methyl]-3-[[(3-ethylphenyl)methyl]amino]-2-hydroxypropyl]amino]-2-oxo-1-[[(1-propylbutyl)sulfonyl]methyl]ethyl]-, phenylmethyl ester, mono(trifluoroacetate) (salt)