Triethylsilane → (1R,2S)-1-{[(1R,2R,4R)-2-(N'-tert-Butoxycarbonyl-N-hept-6-enyl-hydrazinocarbonyl)-4-(7-methoxy-2-phenyl-quinolin-4-yloxy)-cyclopentanecarbonyl]-amino}-2-vinyl-cyclopropanecarboxylic acid ethyl ester

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Reaction Steps

Scaffold molecule 35 (135 mg, 0.225 mmol) and triethylsilane (71 μL, 0.447 mmol) was dissolved in DCM (2 mL) after which trifluoroacetic acid (TFA) (2 mL) was added. The mixture was stirred for 2 h and thereafter co-evaporated with toluene in order to remove the TFA. The residue was dissolved in DMF (3 mL) and 47 (60 mg, 0.263 mmol) and DIEA (118 μL, 0.677 mmol) were added. The temperature was lowered to 0° C. and the coupling reagent O-(7-azabenzotriazol-1-yl)-NNN′,N′-tetramethyluronium hexafluorophosphate (HATU) (94 mg, 0.247 mmol) was added. The cold solution was allowed to stir for half an hour and then for additional 16 h in room temperature. The solvent was removed by heating the reaction flask in a water bath under diminished pressure. The residue was thereafter dissolved in ethyl acetate and the organic phase washed three times with brine, dried, filtered and evaporated. Purification by HPLC (MeOH/H2O 90:10 with 0.2% triethylamine) gave 48 (140 mg, 82%) as an oil.

Provenance & Evidence