Methyl iodide → B-(5-methoxy-1-methyl-1h-pyrrolo[3,2-b]pyridin-6-yl)-boronic acid
Reaction equation
[CH3:1][O:2][C:3]1[N:8]=[C:7]2[CH:9]=[CH:10][NH:11][C:6]2=[CH:5][C:4]=1[B:12]([OH:14])[OH:13].[H-].[Na+].I[CH3:18]>O1CCCC1>[CH3:1][O:2][C:3]1[N:8]=[C:7]2[CH:9]=[CH:10][N:11]([CH3:18])[C:6]2=[CH:5][C:4]=1[B:12]([OH:14])[OH:13]Participants
Procedure
To a white suspension of 5-methoxy-1H-pyrrolo[3,2-b]pyridin-6-ylboronic acid (500 mg, 2.60 mmol) in tetrahydrofuran (25 mL) was added sodium hydride (281 mg, 11.72 mmol) in several portions at 0° C., the resulting light grey suspension was stirred for 30 min, followed by dropwise addition of iodomethane (1664 mg, 11.72 mmol) in syringe. The mixture was continued stirring at 0° C. for 2 hr and the reaction was quenched with conc. HCl at 0° C. to ˜pH 6, MeOH (20 mL) was added, stirred for 2 min, the resulting suspension was passed through a thin layer silica gel with 10 mL MeOH. The collected solution was concentrated on rotary vacuo, and purified on PrepHPLC to afford the expected product, 5-methoxy-1-methyl-1H-pyrrolo[3,2-b]pyridin-6-ylboronic acid (398 mg, 74%) as a grey gum. 1H-NMR (500 MHz, MeOD) δ ppm 3.33 (ddd, J=3.20, 1.83, 1.68 Hz, 3 H) 4.24 (s, 3 H) 6.62 (d, J=2.44 Hz, 1 H) 7.71 (d, J=3.36 Hz, 1 H) 8.39 (s, 1 H); Mass spec 207.16 (MH+) Calc for C9H11BN2O3 206.09.
Workup
- stirringThe mixture was continued stirring at 0° C. for 2 hr
- customthe reaction was quenched with conc. HCl at 0° C.
- additionwas added
- stirringstirred for 2 min
- concentrationThe collected solution was concentrated on rotary vacuo
- custompurified on PrepHPLC
Sources & evidence
- ORD record
- ord-ebb52a3a77c9432ab5fcdcfa453ed4af
- Source dataset
- uspto-grants-2008_12
- Patent number
- US07470680B2
Reaction notes
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