L-Azetidine-2-carboxylic acid → AzeOH D-tartrate
Reaction equation
[NH:1]1[CH2:7][CH2:6][C@H:2]1[C:3]([OH:5])=[O:4].N1CC[C@@H]1C(O)=O.[C:15]([C@@H:18]([C@H:20]([C:22]([O-:24])=[O:23])[OH:21])[OH:19])([O-:17])=[O:16]>>[NH:1]1[CH2:7][CH2:6][C@H:2]1[C:3]([OH:5])=[O:4].[C:15]([C@H:18]([C@@H:20]([C:22]([O-:24])=[O:23])[OH:21])[OH:19])([O-:17])=[O:16]Participants
Conditions
- Temperature
- 95 °C
Procedure
50 g of a mother liquor containing enantiomerically-enriched AzeOH containing 16 g (68% e.e.) of D-AzeOH (prepared in accordance with Example 1) was concentrated under vacuum to give a viscous oil, which was further dewatered by azeotropic distillation with isopropanol. Acetic acid (72 mL) was added to the concentrated residue. The mixture was heated to 95° C. and D-tartaric acid (25 g) and caproic aldehyde (2.8 g) were added. The mixture was seeded with L-AzeOH-D-tartrate, kept at 95-100° C. for 3 hours and then gradually cooled to 0° C. The crystalline product was filtered, washed and dried at 60° C. under vacuum to yield 29.3 g of L-AzeOH-D-tartrate with a d.e. of 94.6%. Recrystallisation of 28 g of the diastereomeric salt from ethanol:water (140 mL; 1.25:1.0) yielded 21.4 g of L-AzeOH-D-tartrate with a d.e. of 100%.
Workup
- concentrationwas concentrated under vacuum
- customto give a viscous oil, which
- distillationwas further dewatered by azeotropic distillation with isopropanol
- additionAcetic acid (72 mL) was added to the concentrated residue
- additionD-tartaric acid (25 g) and caproic aldehyde (2.8 g) were added
- temperaturegradually cooled to 0° C
- filtrationThe crystalline product was filtered
- washwashed
- customdried at 60° C. under vacuum
Sources & evidence
- ORD record
- ord-8b7bea0d327345029efb6535c628e738
- Source dataset
- uspto-grants-2000_11
- Patent number
- US06143903
Reaction notes
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