Methanol → methyl L-prolinate hydrochloride

HRID 129573

Reaktionsgleichung

Reaktionsgleichung von HRID 129573
S(Cl)([Cl:3])=O.[NH:5]1[CH2:12][CH2:11][CH2:10][C@H:6]1[C:7]([OH:9])=[O:8].[CH3:13]O>>[ClH:3].[NH:5]1[CH2:12][CH2:11][CH2:10][C@H:6]1[C:7]([O:9][CH3:13])=[O:8]

Komponenten

4

Edukt 3

HCID 887MethanolHCID 24386Thionyl ChlorideHCID 145742L-Proline

Produkt 1

HCID 2733200methyl L-prolinate hydrochlorideAusbeute 99,6 %

Versuchsvorschrift

Thionyl chloride (65 ml, 0.89 mol) was added dropwise at ice-cooling for 45 min to a solution of L-proline (57.6 g, 0.50 mol) in 500 ml MeOH. The temperature was raised to reflux. After 4 h at reflux the mixture was cooled and the solvent evaporated in vacuo. MeOH was added to the residue and then evaporated repeatedly three times to give 86 g crude methyl (S)-2-pyrrolidinecarboxylate hydrochloride (99.6% purity by GLC) as a thick syrup. The ester (1.65 g, 0.01 mol) was transferred to a flask containing acetaldehyde (2.21 g, 0.05 mol) 10% Pd/C (0.15 g) and 15 ml MeOH. The mixture was shaken in a Parr apparatus at 55 psi hydrogen pressure for 4 h at room temperature, filtered and evaporated to give 2.1 g crude hydrochloride of the title ester. (91% purity by GLC). This material was subjected to aminolysis in Example 7D.

Aufarbeitung

  1. temperatureThe temperature was raised
  2. temperatureto reflux
  3. temperatureAfter 4 h at reflux the mixture
  4. temperaturewas cooled
  5. customthe solvent evaporated in vacuo
  6. additionMeOH was added to the residue
  7. customevaporated repeatedly three times

Quellen und Nachweise

ORD-Eintrag
ord-a970eee38a57465085b49457150c9b32
Quelldatensatz
uspto-grants-1995_11
Patentnummer
US05468876

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