Diisopropylethylamine → HCID 136344049, compound

Participants

Reaction Steps

To a solution of 4-isobutyl-6-methyl-pyridine-2-carboxylic acid (480 mg, 2.09 mmol) and DIPEA (810 mg, 6.27 mmol) in DMF (20 mL), PyBOP (1150 mg, 2.21 mmol) is added at 0° C. The mixture is stirred for 15 min at 0° C. before 3-ethyl-4,N-dihydroxy-5-methyl-benzamidine (429 mg, 2.21 mmol) is added and stirring is continued for 1 h at 0° C. The reaction is quenched by adding water, the mixture is diluted with sat. aq. NaHCO3-solution and extracted twice with EA. The combined org. extracts are dried over MgSO4, filtered and concentrated to give the crude hydroxy-amidine ester intermediate; LC-MS: tR=0.90 min, [M+H]+=370.16. This material is dissolved in dioxane (10 mL) and the mixture is stirred at 80° C. for 15 h. The solvent is evaporated and the crude product is purified by CC on silica gel eluting with heptane:EA 7:3 to give the title compound (112 mg) as a pale purple oil; LC-MS: tR=1.12 min, [M+H]+=352.17.

Provenance & Evidence