Trifluoroacetic acid → N4-[4-tert-butyl-2-(piperidin-4-yloxy)benzoyl]-N3-(4-methoxybenzoyl)-3,4-pyridinediamine

Participants

Reaction Steps

To an ice-water bath-chilled solution of N4-[2-(1-tert-butoxycarbonylpiperidin-4-yloxy)-4-tert-butylbenzoyl]-N3-(4-methoxybenzoyl)-3,4-pyridinediamine (460 mg, 764 micromoles) in dichloromethane (15 mL) was added trifluoroacetic acid (5 mL) and the mixture stirred on ice for 90 min. The mixture was then concentrated in vacuo, the oily residue redissolved in 1:1 dichloromethane:toluene (10 mL) and re-concentrated in vacuo to provide a pale tan-yellow oil. The oil was dissolved in methanol (10 mL) and applied to a 10 gram×60 cubic centimeter strong cation exchange solid phase extraction column (SCX, Varian Sample Preparation Products, Harbor City, Calif.) that had been conditioned with methanol. After sample application, the cartridge was washed with methanol (4×50 mL) and the product was eluted with 3:1 chloroform:(2 M NH3 in methanol) (3×40 mL). The eluates were concentrated in vacuo to afford N4-[4-tert-butyl-2-(piperidin-4-yloxy)benzoyl]-N3-(4-methoxybenzoyl)-3,4-pyridinediamine as a yellow oil (400 mg, 104%). This material was used without further purification.

Provenance & Evidence