Trimethyl orthoformate → methyl L-prolinate hydrochloride

HRID 440072Notes

Reaction equation

HRID 440072 reaction equation
[NH:1]1[CH2:8][CH2:7][CH2:6][C@H:2]1[C:3]([OH:5])=[O:4].S(Cl)([Cl:12])(=O)=O.[CH:14](OC)(OC)OC>CO>[ClH:12].[CH3:14][O:4][C:3](=[O:5])[C@@H:2]1[CH2:6][CH2:7][CH2:8][NH:1]1

Participants

5

Reactant 3

HCID 9005Trimethyl orthoformateHCID 24648Sulfuryl chlorideHCID 145742L-Proline

Product 1

HCID 2733200methyl L-prolinate hydrochlorideYield 225.1%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of L-Proline (115 g,1 mol) in methanol (1.2 L) at 0° C. was added sulfuryl chloride (45 mL, 0.55 mol) slowly during ~15-20 min, then the reaction mixture stirred overnight at room temperature. After 16 hours at room temperature and another 4 hours at reflux, trimethyl orthoformate (120 mL, 1.1 mol) was added and heating at reflux continued for another 24 hr. The reaction mixture was then concentrated and the resultant oil was placed under high vacuum for several days to afford the product as a clear oil (205 g).

Workup

  1. waitAfter 16 hours at room temperature
  2. temperatureanother 4 hours at reflux
  3. temperatureheating
  4. temperatureat reflux
  5. waitcontinued for another 24 hr
  6. concentrationThe reaction mixture was then concentrated
  7. waitthe resultant oil was placed under high vacuum for several days

Sources & evidence

ORD record
ord-b653a5c91e364949827e605624fc2e60
Source dataset
uspto-grants-1996_05
Patent number
US05516912

Reaction notes

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