2-Dicyclohexylphosphino-2',6'-dimethoxybiphenyl → ethyl 3-(6-chloro-1-trityl-1H-pyrazolo[4,3-c]pyridin-3-yl)propanoate

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Reaction Conditions

Reaction Steps

An oven-dried, nitrogen cooled 2 ml microwave vial was charged with 6-chloro-3-iodo-1-trityl-1H-pyrazolo[4,3-c]pyridine (Intermediate 3a, 103 mg, 0.197 mmol), palladium (II) acetate (2.2 mg, 9.80 μmol) and SPhos (8.2 mg, 0.020 mmol), sealed under an argon atmosphere, charged with (3-ethoxy-3-oxopropyl)zinc(II) bromide (0.5 M in THF, 0.5 ml, 0.250 mmol) and heated to 40° C. for 23 hr. Quenched with MeOH, filtered through celite, concentrated in vacuo and purified via flash chromatography (0-100% EtOAc/Hex). Obtained ethyl 3-(6-chloro-1-trityl-1H-pyrazolo[4,3-c]pyridin-3-yl)propanoate (32.6 mg, 0.066 mmol, 33.3% yield) as a yellow residue. MS ESI calc'd for C30H26ClN3O2 [M+H]+=496, found 496.

Provenance & Evidence