A simple and efficient synthesis of phthalazin-1 (2H)-one 2-substituted derivatives is achieved in very good yields via reaction of a phthalazinone–trichloroacetimidate with various C-and O-nucleophiles such as aromatic, heteroaromatic and olefinic reagents, sugars and cholesterol in CH2Cl2 in the presence of a catalytic amount of trimethylsilyl trifluoromethanesulfonate (TMSOTf).
