Phthalic Anhydride → (2S)-2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-propionic acid tert-butyl ester

HRID 2110812Notes

Reaction equation

HRID 2110812 reaction equation
Cl.[C:2]([O:6][C:7](=[O:11])[C@H:8]([CH3:10])[NH2:9])([CH3:5])([CH3:4])[CH3:3].C(N(C(C)C)CC)(C)C.[C:21]1(=O)[O:26][C:24](=[O:25])[C:23]2=[CH:27][CH:28]=[CH:29][CH:30]=[C:22]12>C1(C)C=CC=CC=1.CCOCC>[C:2]([O:6][C:7](=[O:11])[C@@H:8]([N:9]1[C:24](=[O:25])[C:23]2[C:22](=[CH:30][CH:29]=[CH:28][CH:27]=2)[C:21]1=[O:26])[CH3:10])([CH3:5])([CH3:4])[CH3:3]

Participants

6

Reactant 3

HCID 6811Phthalic AnhydrideHCID 81531DiisopropylethylamineHCID 11275390tert-Butyl alaninate hydrochloride

Product 1

HCID 13005797(2S)-2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-propionic acid tert-butyl esterYield 90%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 3283Diethyl EtherSolvent

Procedure

A suspension of (2S) alanine tert-butyl ester hydrochloride (2.05 g, 11.2 mmol), diisopropylethylamine (1.83 mL, 10.6 mmol) and phthalic anhydride (1.48 g, 10 mmol) in toluene (10 mL) was refluxed for 3 hours under Dean-Stark conditions. The reaction was cooled to room temperature, diluted with Et2O, washed with 1N HCl and then with aq.sat. NaHCO3. The organic layer was dried (MgSO4), filtered and evaporated to afford the sub-title compound as a white powder (2.465 g, 90%): 1H NMR (400 MHz CDCl3) δ 1.45 (9H, s), 1.68 (3H, d), 4.90 (1H, q), 7.75 (2H, d), 7.88 (2H, d)

Workup

  1. temperaturewas refluxed for 3 hours under Dean-Stark conditions
  2. washwashed with 1N HCl
  3. dry with materialThe organic layer was dried (MgSO4)
  4. filtrationfiltered
  5. customevaporated

Sources & evidence

ORD record
ord-fbf1b0d61f6244fc8ca95ce1bc39d8c7
Source dataset
uspto-grants-2009_04
Patent number
US07517987B2

Reaction notes

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