1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → (5-Benzyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-(4,6-dimethyl-pyrimidin-5-yl)-methanone

Participants

Reaction Steps

To a mixture of 4,6-dimethyl-pyrimidine-5-carboxylic acid (0.85 g, 5.58 mmol, T. J. Kress et. al. Heterocycles 1994 38:1375) and 16a (1.13 g, 5.58 mmol, C. J. Ohnmacht et al. J. Heterocycl. Chem. 1983 20:321) in DCM (25 mL) at RT was added sequentially EDCI (1.43 g, 6.7 mmol), HOBt (0.9 g, 6.7 mmol) and DIPEA (3.9 mL, 22.34 mmol) and the mixture was stirred overnight at RT. The reaction mixture was washed with 5% NaHCO3 solution, dried (MgSO4) and concentrated in vacuo. The crude product was purified by flash chromatography on silica gel eluting with MeOH (containing 10% NH4OH)/DCM (0 to 4%) to afford 1.5 g of (5-benzyl-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl)-(4,6-dimethyl-pyrimidin-5-yl)-methanone: ms (ES+) m/z 337 (M+H)+. To a solution of amide from the previous step (1.5 g, 4.45 mmol) in MeOH (50 mL) was added ammonium formate (2.81 g, 44.58 mmol). Palladium on charcoal previously wetted with MeOH was slowly added and the mixture heated to reflux for 8 h. The catalyst was filtered and solvent evaporated. The residue was purified by flash chromatography on silica gel eluting with MeOH (containing 10% NH4OH)/DCM (0 to 4%) to afford 0.941 g of 38 (Ar2=4,6-dimethyl-pyrimidin-5-yl): ms (ES+) m/z 247 (M+H)+.

Provenance & Evidence