Isovaleric Acid → N-{3-[3-(4-Cyanoanilino)propyl]-3-azabicyclo[3.2.1]oct-8-yl}-N,3-dimethylbutanamide

Participants

Reaction Steps

1,3-Dicyclohexylcarbodiimide on N-methylpolystyrene (0.67 g of 2.39 mmol/g, 1.74 mmol) was added to a solution of 4-({3-[8-(methylamino)-3-azabicyclo[3.2.1]oct-3-yl]propyl}amino)benzonitrile (Peparation G; 74.6 mg, 0.25 mmol) in DMF (3.0 mL). A solution of 3-methylbutyric acid (105.0 mg, 1.02 mmol) in DCM (1.0 mL) was added, and the mixture was stirred overnight at rt, followed by a further 72 h at 50° C. Polystyrene isocyanate (150 mg) and DCM (1.5 mL) were added, and this mixture was stirred for 1.5 h. K2CO3 (75 mg) was added and the mixture stirred for an additional 5 h. The solvents were evaporated and DCM (3 mL) was added to the resulting residue. This mixture was added to an ion-exchange solid-phase extraction plug (CBA). The plug was washed with DCM:MeCN (4:1; 10 mL). The product was then eluted with DCM:MeOH:TEA (90:5:5; 7.5 mL) to give 75 mg (70.9%) of the title compound.

Provenance & Evidence