Chemical Structure from Scientific Research

Reaction conditions: a Pyridines (0.2 mmol, 1.0 equiv.), Tf 2 O (0.2 mmol, 1.0 equiv.), ethyl acetate (1.0 mL), -78 C, 0.5 h, then dibenzylamine (0.24 mmol, 1.2 equiv.), 2,4,6-collidine (0.2 mmol, 1.0 equiv.), 60 C, 1.0 h, then 15 NH 4 Cl (0.6 mmol, 3.0 equiv.), triethylamine (1.2 mmol, 6.0 equiv.), acetonitrile (2.0 mL), 100 C, 1 h. Yields of isolated products are shown. Isotopic enrichment (IE) expresses the percentage of 15 N in the isolated product and was determined by HRMS. b Imine intermediate was isolated by precipitation and then used in the labeling step. *Yields of isolated imines. 1 H-NMR yields using dibromomethane as an internal standard. c Dichloromethane was used instead of ethyl acetate and the reaction temperature was 25 C in the first step.

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