Trimethyl borate → methyl hydrogen 5-methoxy-1-(triisopropylsilyl)-1H-pyrrolo[3,2-b]pyridin-6-ylboronate

To a colorless solution of 5-methoxy-1-(triisopropylsilyl)-1H-pyrrolo[3,2-b]pyridine (5.01 g, 16.45 mmol) in THF (100 mL) was dropwise added 2nd-BuLi (21.15 mL, 29.6 mmol) at −78° C. under N2 over 5 min to give an orange solution, the mixture was stirred for 30 min, followed by dropwise addition of trimethyl borate (3.31 mL, 29.6 mmol) through a syringe over 1 min. The resulting light orange solution was stirred at −78° C. for 1 hr, quenched with sat. NH4Cl (30 mL), partitioned between H2O/Et2O (100 mL/150 mL). After seperation, the organic layer was washed with brine (50 mL), dried on MgSO4, concentrated on rotary vacuo and purified on Biotage Flash Collector eluting with 10˜50% EtOAc/Hexanes (1300 mL) to afford the expected produce methyl hydrogen 5-methoxy-1-(triisopropylsilyl)-1H-pyrrolo[3,2-b]pyridin-6-ylboronate (2.5 g, 42%), as a colorless thick gum. Mass spec. 363.24 (MH+) calc. for C18H31,BN2O3 Si 362.22.

1. customto give an orange solution
2. stirringThe resulting light orange solution was stirred at −78° C. for 1 hr
3. customquenched with sat. NH4Cl (30 mL)
4. custompartitioned between H2O/Et2O (100 mL/150 mL)
5. customAfter seperation
6. washthe organic layer was washed with brine (50 mL)
7. customdried on MgSO4
8. concentrationconcentrated on rotary vacuo
9. custompurified on Biotage Flash Collector
10. washeluting with 10˜50% EtOAc/Hexanes (1300 mL)
11. customto afford the

ORD record

ord-9dec04fb0d274f2db7bb3bea8825a834

Source dataset

uspto-grants-2008_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07470680B2