Sulfuric Acid → HCID 53857518, compound

HRID 849733Notes

Reaction equation

HRID 849733 reaction equation
[CH2:1]=[C:2]([CH3:4])[CH3:3].C(Cl)(Cl)Cl.C(=O)=O.[Br:12][C@H:13]([CH2:17][CH:18]([CH3:20])[CH3:19])[C:14]([OH:16])=[O:15].S(=O)(=O)(O)O>ClCCl>[C:2]([O:16][C:14](=[O:15])[C@H:13]([Br:12])[CH2:17][CH:18]([CH3:20])[CH3:19])([CH3:4])([CH3:3])[CH3:1]

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 8255IsobutyleneHCID 12697060(2R)-2-bromo-4-methylpentanoic acidHCID 86583683HCID 86583683, compound

Product 1

HCID 53857518HCID 53857518, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Into dichloromethane (80 mL) was condensed isobutene to double the volume (at -50° C. CHCl3 /dry ice). To this solution was added (2R)-2-bromo-4-methylpentanoic acid (28 g, 143.6 mmol) and maintaining the temperature between -400 and -50° C. concentrated sulphuric acid (1 mL) was added dropwise. The reaction was then allowed to warm to room temperature over 20 hours. The solution was then concentrated before adding additional methylene chloride (300 mL) which was subsequently washed with saturated NaHCO3 (2×100 mL) followed by water (2×100 mL). After drying over Na2SO4, the organic layer was filtered and concentrated to give a yellow oil. The material was distilled to give 23 g of (2R)-2-bromo-4-methylpentanoic acid t-butyl ester as a clear colorless oil.

Workup

  1. additionwas added dropwise
  2. concentrationThe solution was then concentrated
  3. additionbefore adding additional methylene chloride (300 mL) which
  4. washwas subsequently washed with saturated NaHCO3 (2×100 mL)
  5. dry with materialAfter drying over Na2SO4
  6. filtrationthe organic layer was filtered
  7. concentrationconcentrated
  8. customto give a yellow oil
  9. distillationThe material was distilled

Sources & evidence

ORD record
ord-4b96ee3d28104edb8caee1af9f54b43c
Source dataset
uspto-grants-2000_01
Patent number
US06013792

Reaction notes

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