p-Toluenesulfonic acid monohydrate → (S)-neopentyl 2-aminopropanoate p-toluenesulfonic acid

HRID 408974Notes

Reaction equation

HRID 408974 reaction equation
C(OC([NH:8][C@@H:9]([CH3:18])[C:10]([O:12][CH2:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:11])=O)(C)(C)C.[CH3:19][C:20]1[CH:21]=[CH:22][C:23]([S:26]([OH:29])(=[O:28])=[O:27])=[CH:24][CH:25]=1.O>C(OCC)(=O)C>[C:20]1([CH3:19])[CH:21]=[CH:22][C:23]([S:26]([OH:29])(=[O:27])=[O:28])=[CH:24][CH:25]=1.[NH2:8][C@@H:9]([CH3:18])[C:10]([O:12][CH2:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:11]

Participants

4

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 86662565Neopentyl (tert-butoxycarbonyl)-L-alaninate

Product 1

HCID 86662564(S)-neopentyl 2-aminopropanoate p-toluenesulfonic acidYield 79%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
65 °C

Procedure

The conversion was carried out using a 22 L 3-neck open head flask equipped with a mechanical stirrer and an internal thermocouple. To a stirred solution of (S)-neopentyl 2-(tert-butoxycarbonylamino)propanoate (900 g, 3.47 mol) in 14 L of ethyl acetate was added PTSA.H2O (660 g, 3.47 mol, 98% reagent grade, Product No 161993, Aldrich) and heated at 65° C. for 10 h. The mixture was cooled to give white solid at room temperature and cooled at ice bath for 30 min prior to filtration. The mixture solution was filtered and dried in a vacuum oven (40° C., Welch Model 2034, ca. 10 mmHg) for 15 hr to yield 907 g (2.74 mol, 79%) of desired product.

Workup

  1. customequipped with a mechanical stirrer
  2. temperatureThe mixture was cooled
  3. customto give white solid at room temperature
  4. temperaturecooled at ice bath for 30 min
  5. filtrationto filtration
  6. filtrationThe mixture solution was filtered
  7. customdried in a vacuum oven (40° C., Welch Model 2034, ca. 10 mmHg) for 15 hr

Sources & evidence

ORD record
ord-c2ca00405d7b4005b65d8a606fa697f2
Source dataset
uspto-grants-2014_06
Patent number
US08759318B2

Reaction notes

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