Triethylamine → HCID 178441456, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-butyl-3-iodo-1H-pyrazolo[4,3-d]pyrimidin-7(6H)-one (4.97 g, 15.62 mmol) in N,N-dimethylformamide (100 mL) was added bis(triphenylphosphine)palladium(II)dichloride (1.228 g, 1.750 mmol) and copper(I) iodide (0.595 g, 3.12 mmol). The solution was stirred and degassed with nitrogen for 5 minutes then the reaction mixture placed under a nitrogen atmosphere. A solution of 6-chloro-1-hexyne (3.64 g, 31.2 mmol) and triethylamine (4.36 mL, 31.2 mmol) in N,N-dimethylformamide (30 mL) was added dropwise over 10 minutes. The reaction mixture was stirred at ambient temperature for a further 10 minutes then heated to 60° C. for 2.5 hours. The reaction mixture was concentrated in vacuo at 60° C. and the resulting residue partitioned between ethyl acetate (250 mL) and a 1:1 mixture of water:brine (500 mL). The organic layer was separated and the aqueous layer back extracted with ethyl acetate (250 mL). The combined organic phases were dried through a hydrophobic frit and concentrated in vacuo to give a brown solid (8.0 g). The residue was dissolved in a 1:1 mixture of MeOH:DCM and absorbed onto Florisil. The solid was loaded and purified by chromatography on silica (330 g) using a 0-100% ethyl acetate-cyclohexane gradient over 10 column volumes followed by flushing with ethyl acetate for 9 column volumes. The appropriate fractions were combined and evaporated in vacuo to give a yellow solid (3.55 g). The solid was triturated with diisopropyl ether, filtered and dried in vacuo at 50° C. to give the title compound as a pale yellow solid (3.14 g).

Provenance & Evidence