The ω-hydroxy acid derivative of PEG37 (3, 5 g, 2.38 mmol) and tert-butyl carbazate (0.91 g, 6.9 mmol) are dissolved in CH2Cl2-ethyl acetate (1:1, 7 ml). The solution is cooled on ice and treated with (DCC) (0.
4-difluorobenzoyl)-2-oxopyridin-1(2H)-yl]-3,5-difluorophenyl}ethyl)-L-alaninate or a salt, hydrate or solvate thereof. The present invention also provides a pharmaceutical composition comprising the compound together with one or more pharmaceutically acceptable carriers and/or excipients. The...