Lithium Hydroxide → N-(tert-Butoxycarbonyl)-4-carbamoyl-2,6-dimethyl-L-phenylalanine

HRID 1620136Notes

Reaction equation

C[O:2][C:3](=[O:25])[C@@H:4]([NH:17][C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH2:5][C:6]1[C:11]([CH3:12])=[CH:10][C:9]([C:13](=[O:15])[NH2:14])=[CH:8][C:7]=1[CH3:16].[Li+].[OH-]>C1COCC1>[C:21]([O:20][C:18]([NH:17][C@@H:4]([CH2:5][C:6]1[C:11]([CH3:12])=[CH:10][C:9]([C:13](=[O:15])[NH2:14])=[CH:8][C:7]=1[CH3:16])[C:3]([OH:25])=[O:2])=[O:19])([CH3:24])([CH3:23])[CH3:22]

Participants

Conditions

Temperature: 0 °C

Procedure

Into an ice-cooled solution of methyl ester from Step C (2.99 g, 8.54 mmol) in THF (50 mL) was added an aqueous LiOH solution (1N, 50 mL) and stirred at 0° C. Upon consumption of the starting materials, the organic solvents were removed and the aqueous phase was neutralized with cooled 1N HCl at 0° C., and extracted with EtOAc, and dried over Na2SO4 overnight. Filtration and evaporation to dryness led to the title acid (S)-2-tert-butoxycarbonylamino-3-(4-carbamoyl-2,6-dimethylphenyl)propionic acid (2.51 g, 87%); 1H NMR (300 MHz, DMSO-d6): δ 1.30 (9H, s), 2.32 (6H, s), 2.95 (1H, dd, J=8.8, 13.9 Hz), 3.10 (1H, dd, J=6.2, 14.0 Hz), 4.02-4.12 (1H, m), 7.18-7.23 (2H, m), 7.48 (2H, s), 7.80 (1H, s); MS (ES+) (relative intensity): 236.9 (6) (M-Boc)+.

Workup

customUpon consumption of the starting materials
customthe organic solvents were removed
temperaturewith cooled 1N HCl at 0° C.
extractionextracted with EtOAc
dry with materialdried over Na2SO4 overnight
filtrationFiltration and evaporation to dryness

Sources & evidence

ORD record: ord-2e3831ed21d7460aa9d2c680b7ae40b2
Source dataset: uspto-grants-2014_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08772325B2

Reaction notes

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