2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → HCID 59541023, compound

HRID 1677423Notes

Reaction equation

HRID 1677423 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]([O:13][CH3:14])=[C:6]([N:8]2[CH2:12][CH2:11][CH2:10][CH2:9]2)[CH:7]=1.[Li]C(C)(C)C.C(O[B:24]1[O:28][C:27]([CH3:30])([CH3:29])[C:26]([CH3:32])([CH3:31])[O:25]1)(C)C>C1COCC1>[CH3:14][O:13][C:5]1[CH:4]=[CH:3][C:2]([B:24]2[O:28][C:27]([CH3:30])([CH3:29])[C:26]([CH3:32])([CH3:31])[O:25]2)=[CH:7][C:6]=1[N:8]1[CH2:12][CH2:11][CH2:10][CH2:9]1

Participants

5

Reactant 3

HCID 50177412-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 59540722HCID 59540722, compoundHCID 178418306HCID 178418306, compound2×

Product 1

HCID 59541023HCID 59541023, compoundYield 36%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a −78° C. solution of 1-(5-bromo-2-methoxy-phenyl)-pyrrolidine (270 mg, 1.1 mmol) in THF (17 mL) was added dropwise a solution of t-BuLi (1.3 mL, 1.7 M solution in pentane, 2.2 mmol). The resultant yellow solution was stirred for 30 min, treated with additional t-BuLi (1.3 mL, 1.7 M solution in pentane, 2.2 mmol), stirred for 45 min, and treated dropwise with 2-isopropoxy-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (0.8 mL, 4.4 mmol). The reaction was allowed to slowly warm to room temperature, stirred at room temperature overnight, and partitioned between saturated NH4Cl and EtOAc. The combined organic phases were dried with Na2SO4 and concentrated to give a tan oil. The crude product was purified by flash chromatography using 25 g of silica gel and 0-50% EtOAc in hexanes as eluant to afford 120 mg (35%) of 1-[2-methoxy-5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-pyrrolidine as a white solid. M+H 304.

Workup

  1. stirringstirred for 45 min
  2. stirringstirred at room temperature overnight
  3. custompartitioned between saturated NH4Cl and EtOAc
  4. dry with materialThe combined organic phases were dried with Na2SO4
  5. concentrationconcentrated
  6. customto give a tan oil
  7. customThe crude product was purified by flash chromatography

Sources & evidence

ORD record
ord-ec1c1d3185b2450db95612744d406ef9
Source dataset
uspto-grants-2011_08
Patent number
US08008298B2

Reaction notes

Loading…