Hydrochloric Acid → Diethyl (1S,2S,5R,6S)-2-aminospiro[bicyclo[3.1.0]hexane-4,1'-cyclopropane]-2,6-dicarboxylate hydrochloride
Reaction equation
[ClH:1].C(OC([NH:12][C@@:13]1([C:26]([O:28][CH2:29][CH3:30])=[O:27])[CH2:20][C:17]2([CH2:19][CH2:18]2)[C@@H:16]2[C@H:14]1[C@H:15]2[C:21]([O:23][CH2:24][CH3:25])=[O:22])=O)C1C=CC=CC=1>[Pd].C(O)C>[ClH:1].[NH2:12][C@@:13]1([C:26]([O:28][CH2:29][CH3:30])=[O:27])[CH2:20][C:17]2([CH2:19][CH2:18]2)[C@@H:16]2[C@H:14]1[C@H:15]2[C:21]([O:23][CH2:24][CH3:25])=[O:22]Participants
Conditions
- Temperature
- 25 °C
Procedure
Charge absolute ethanol (100 mL, 10 volumes), concentrate. HCl (2.1 mL, 1.0 N) and diethyl (1S,2S,5R,6S)-2-benzyloxycarbonylaminospiro[bicyclo[3.1.0]hexane-4,1′-cyclopropane]-2,6-dicarboxylate (9.7 g, 24.16 mmol) to a HEL reactor followed by Pd black (3.9 g, 40 wt %). Purge the reactor three times with nitrogen followed by three hydrogen purges and pressurization to 40 psi hydrogen. Allow the reaction to stir between 20-30° C. for at least two hours until the completion of the reaction monitored by HPLC. Filter the resulting slurry through a pad of Hyflo Super Cel® and wash the wet cake with absolute ethanol (2×30 mL, 3 volumes). Transfer the filtrate to a clean reactor and displace ethanol with isopropyl acetate to approximately 5 volumes based on in-situ product yield from calibration curve. Cool the resulting slurry to 0-5° C. over at least 3 hours. Filter the resulting slurry and wash the wet cake washed with cold isopropyl acetate (3×5 mL, 0.5 volumes). Dry under reduced pressure at 30° C. for at least 12 hours to provide the title compound (4.66 g, 15.34 mmol 63.5%) 1H NMR (DMSO-d6, 400 MHz): δ 8.84 (s, 3H), 4.31-4.15 (m, 2H), 4.03 (q, J=7.0, 2H), 2.42 (dd, J=3.1, 2.6, 1H), 2.24 (dd, J=6.2, 2.6, 1H), 1.94 (d, J=14.1, 1H), 1.68 (d, J=14.1, 1H), 1.63 (dd, J=6.6, 3.1, 1H), 1.25 (t, J=7.0, 3H), 1.17 (t, J=7.0, 3H), 0.77-0.71 (m, 1H), 0.65-0.59 (m, 1H), 0.56-0.51 (m, 1H), 0.50-0.44 (m, 1H).
Workup
- concentrationconcentrate
- customPurge the reactor three times with nitrogen
- customthe reaction
- filtrationFilter the resulting slurry through a pad of Hyflo Super Cel®
- washwash the wet cake with absolute ethanol (2×30 mL, 3 volumes)
- customTransfer the filtrate to a clean reactor and displace
- customyield from calibration curve
- temperatureCool the resulting slurry to 0-5° C. over at least 3 hours
- filtrationFilter the resulting slurry
- washwash the wet cake
- washwashed with cold isopropyl acetate (3×5 mL, 0.5 volumes)
- customDry under reduced pressure at 30° C. for at least 12 hours
Sources & evidence
- ORD record
- ord-9da9a73991014734a4a325ff43135149
- Source dataset
- uspto-grants-2013_11
- Patent number
- US08575214B2
Reaction notes
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