Triphenylphosphine → (2S)-2-(tert-Butoxy)-2-[(20S)-16-fluoro-4,20,26-trimethyl-19,25-dioxa-1,5,7,8-tetraazapentacyclo[24.2.2.16,9.02,7.013,18]hentriaconta-2,4,6(31),8,10,13(18),14,16-octaen-3-yl]acetic acid

Participants

Reaction Steps

To a solution of (S)-ethyl 2-(tert-butoxy)-2-(2-(3-(4-fluoro-2-hydroxyphenyl)prop-1-en-1-yl)-7-(4-(((R)-5-hydroxyhexyl)oxy)-4-methylpiperidin-1-yl)-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)acetate (240 mg, 0.367 mmol) in THF (50 mL) at 0° C. was added Ph3P (144 mg, 0.550 mmol) followed by DEAD (0.087 mL, 0.550 mmol) and the resulting mixture was stirred at room temp for 3 h. At this point LCMS indicated completion of reaction and desired product as mixture of four isomers. Water (25 mL) was then added and the mixture was extracted with ether (50 mL), dried (Na2SO4), filtered and concentrated. The residue was then purified by Biotage (0-30% EtOAc/hexane) to afford to afford desired ester (165 mg, 0.259 mmol, 70.7% yield) as a inseparable mixture of two isomers which was used in the next step without further purification. LCMS (M+H)=637.3

Provenance & Evidence