2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → HCID 58438616, compound

HRID 1898577Notes

Reaction equation

HRID 1898577 reaction equation
Br[C:2]1[CH:3]=[C:4]([N:8]2[CH2:12][CH2:11][C:10]([CH3:14])([CH3:13])[CH2:9]2)[CH:5]=[CH:6][CH:7]=1.C([Li])(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>[CH3:13][C:10]1([CH3:14])[CH2:11][CH2:12][N:8]([C:4]2[CH:5]=[CH:6][CH:7]=[C:2]([B:24]3[O:28][C:27]([CH3:30])([CH3:29])[C:26]([CH3:32])([CH3:31])[O:25]3)[CH:3]=2)[CH2:9]1

Participants

5

Reactant 3

HCID 50177412-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 57516628HCID 57516628, compoundHCID 178418306HCID 178418306, compound

Product 1

HCID 58438616HCID 58438616, compoundYield 75.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

1-(3-Bromophenyl)-3,3-dimethyl-pyrrolidine (6.7 g, 26.4 mmol) was suspended in 132 ml of THF and cooled to −78° C. in a dry ice acetone bath. tert-Butyl lithium (1.7 M solution in pentane, 46.6 ml, 79.2 mmol) was added dropwise and the reaction was stirred at −78° C. for 15 min. 2-Isopropoxy-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (10.8 ml, 52.8 mmol) was added and the reaction was stirred at −78° C. for 2 h. The reaction was quenched with saturated aqueous ammonium chloride and warmed to room temperature. Water was added and the layers were separated. The aqueous layer was back extracted twice with ethyl acetate. The combined organic layers were dried, filtered and concentrated. The crude product was chromatographed using a gradient of 0% to 10% ethyl acetate in hexanes to give 6.0 g (75%) of 3,3-dimethyl-1-[3 (4,4,5,5-tetramethyl[1,3,2]dioxaborolan-2-yl)-phenyl]-pyrrolidine.

Workup

  1. stirringthe reaction was stirred at −78° C. for 2 h
  2. customThe reaction was quenched with saturated aqueous ammonium chloride
  3. temperaturewarmed to room temperature
  4. additionWater was added
  5. customthe layers were separated
  6. extractionThe aqueous layer was back extracted twice with ethyl acetate
  7. customThe combined organic layers were dried
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customThe crude product was chromatographed

Sources & evidence

ORD record
ord-3fcae81e573c47bfb119f61e87e9a235
Source dataset
uspto-grants-2013_08
Patent number
US08518945B2

Reaction notes

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