Benzophenone imine → tert-Butyl 4-(2-aminoisonicotinoyl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-(2-chloroisonicotinoyl)piperazine-1-carboxylate (17-1, 524 mg) in dry toluene (10 mL) was added NaOtBu (216 mg, 2.25 mmole), racemic BINAP (150 mg, 0.24 mmole), Pd2(dba)3 (74 mg, 0.08 mmole), and benzophenone imine (0.32 mL, 1.93 mmole) then the mixture was heated to 80° C. After 18 hr the mixture was cooled to RT. A solution of 1N HCl:THF (1:1) was added and stirring continued. After 4 hr the mixture was neutralized with saturated NaHCO3 and extracted with EtOAc (3×). The combined organic layers were dried (MgSO4), filtered, and concentrated. Flash column chromatography (gradient, 50-100% EtOAc/hexanes then 0-10%MeOH/CH2Cl2) gave the titled compound as a yellow solid. 1H-NMR (500 MHz, CDCl3) δ8.12 (d, 1H, J=5.13 Hz), 6.58 (d, 1H, J=5.13 Hz), 6.47 (s, 1H), 4.55 (bs, 2H), 3.72-3.36 (m, 4H), 1.47 (s, 9H); MS (ES) (M+H)+307.

Provenance & Evidence