Diisopropylethylamine → 4-{3-[7-(3-tert-butoxycarbonylamino-cyclopentylcarbamoyl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazin-2-yl]-6-fluoro-indazol-1-yl}-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

A 10 ml round-bottomed flask was charged with 2-[1-(1-tert-butoxycarbonyl-piperidin-4-yl)-6-fluoro-1H-indazol-3-yl]-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid (85 mg, 0.14 mmol) and (3-aminocyclopentyl)-carbamic acid tert-butyl ester hydrochloride (50 mg, 0.21 mmol). Then, DMF (1 ml) was added followed by N,N-diisopropylethylamine (0.07 ml, 0.40 mmol) and HATU (59 mg, 0.155 mmol). The reaction mixture was stirred at room temperature overnight then quenched with water and extracted with diethyl ether (2×). The combined organic layers were washed twice with water and once with brine then dried over sodium sulfate, filtered and concentrated. The residue was chromatographed over 12 g silica gel with EtOAc/hexanes (gradient: 0-50% EtOAc) to afford 121 mg (99%) of 4-{3-[7-(3-tert-butoxycarbonylamino-cyclopentylcarbamoyl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazin-2-yl]-6-fluoro-indazol-1-yl}-piperidine-1-carboxylic acid tert-butyl ester as a light yellow oil. The isolated product was determined to be a single diastereomer of unknown relative stereochemistry by NMR analysis.

Provenance & Evidence