2,4-Bis(O-methoxypolyethylene glycol)-6-chloro-s-triazine, a protein modifier with two polyethylene glycol chains (activated PEG2) was synthesized from monomethoxypolyethylene glycol and cyanuric chloride using zinc oxide as a catalyst by the improved method of a previous study (Matsushima et al., Chem. Lett. 7, 773, 1980). The product was identified as activated PEG2 without contamination of by-products with chromatographic and structural analysis.