A solution of {1-[(5-methylisoxazol-3-yl)carbonyl]piperidin-4-yl}acetic acid (2.0 mg, 0.0079 mmol), N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)uronium hexafluorophosphate (8.1 mg, 0.021 mmol) in N,N-dimethylformamide (0.1 mL) and N,N-diisopropylethylamine (3.2 uL) was stirred for 15 minutes. A solution of 6-fluoro-2,4,8,18,22-pentaazatetracyclo[14.3.1.1(3,7).1(9,13)]docosa-1(20),3(22),4,6,9(21),10,12,16,18-nonaen-12-amine tris(trifluoroacetate) (2.5 mg, 0.0078 mmol) in N,N-dimethylformamide (0.04 mL) and was added to the previous solution and stirred overnight. The reaction mixture was purified by preparative HPLC (pH 2) to give the desired product (0.5 mg, 14%). LCMS for C29H30FN8O3 (M+H)+: m/z=557.1.
