Sulfuric Acid → (R)-tert-Butyl 2-chloropropanoate

HRID 708398Notes

Reaction equation

HRID 708398 reaction equation
S([O-])([O-])(=O)=O.[Mg+2].S(=O)(=O)(O)O.[Cl:12][C@H:13]([CH3:17])[C:14]([OH:16])=[O:15].[C:18](O)([CH3:21])([CH3:20])[CH3:19].C(=O)(O)[O-].[Na+]>C(Cl)Cl>[Cl:12][C@H:13]([CH3:17])[C:14]([O:16][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:15]

Participants

7

Reactant 5

HCID 1118Sulfuric AcidHCID 6386tert-ButanolHCID 24083Sulfuric acid magnesium salt (1:1)HCID 516892Sodium BicarbonateHCID 27245402-Chloropropionic acid, (+)-

Product 1

HCID 10986598(R)-tert-Butyl 2-chloropropanoateYield 94.4%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Prepared according to Wright et al. Tetrahedron Lett. 1997, 38, 7345. A 500 mL glass bomb was charged with magnesium sulfate (4.21 g, 35.0 mmol) and DCM (43.8 mL). To this suspension was added sulfuric acid (486 μL, 8.75 mmol), drop-wise with vigorous stirring. After 15 min of stirring, (R)-2-chloropropanoic acid (950 mg, 8.75 mmol) was added followed by tert-butanol (4.20 ml, 43.8 mmol). The bomb was sealed and stirred at rt for 19 h, whereupon sodium bicarbonate (aq satd, 100 mL) was carefully added, at which point all solids had dissolved. The layers were separated and the aqueous layer was extracted with DCM (2×). The combined organics layers were washed with brine, dried over Na2SO4 and concentrated in vacuo (20° C. bath, 50 mBar) to afford the title compound (1.36 g, 94%) as a light pink oil. 1H NMR (500 MHz, CDCl3) δ 4.29 (q, J=6.9 Hz, 1H) 1.65 (d, J=6.9 Hz, 3H) 1.49 (s, 9H).

Workup

  1. customPrepared
  2. customThe bomb was sealed
  3. additionwas carefully added, at which point all solids
  4. dissolutionhad dissolved
  5. customThe layers were separated
  6. extractionthe aqueous layer was extracted with DCM (2×)
  7. washThe combined organics layers were washed with brine
  8. dry with materialdried over Na2SO4
  9. concentrationconcentrated in vacuo (20° C. bath, 50 mBar)

Sources & evidence

ORD record
ord-4c78690346ff488f850b83ae9dcd16ba
Source dataset
uspto-grants-2015_11
Patent number
US09174978B2

Reaction notes

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