N-[4-methoxybenzenesulfonyl]-(D)-valine → N-[(4-methoxyphenyl)sulfonyl]-D-valine tert-butyl ester

HRID 2297977Notes

Reaction equation

HRID 2297977 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([S:9]([NH:12][C@H:13]([CH:17]([CH3:19])[CH3:18])[C:14]([OH:16])=[O:15])(=[O:11])=[O:10])=[CH:5][CH:4]=1.C(NC(=NC(C)C)O[C:26]([CH3:29])([CH3:28])[CH3:27])(C)C>C(Cl)Cl>[C:26]([O:15][C:14](=[O:16])[C@H:13]([NH:12][S:9]([C:6]1[CH:7]=[CH:8][C:3]([O:2][CH3:1])=[CH:4][CH:5]=1)(=[O:11])=[O:10])[CH:17]([CH3:19])[CH3:18])([CH3:29])([CH3:28])[CH3:27]

Participants

4

Reactant 2

HCID 1133588N-[4-methoxybenzenesulfonyl]-(D)-valineHCID 110417822-tert-Butyl-1,3-diisopropylisourea

Product 1

HCID 10807324N-[(4-methoxyphenyl)sulfonyl]-D-valine tert-butyl ester

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

To an ice-cooled solution of 2(R)-(4-methoxybenzenesulfonylamino)-3-methylbutyric acid (30 g, 104.4 mmol), [prepared as described in Example 2, step 1 above], in methylene chloride was added N,N′-diisopropyl-O-tert-butylisourea [can be prepared by the procedure described in Lon J. Mathias, Synthesis, 561-576, (1979)] (75 mL, 3.5 M solution) via additional funnel over 45 min. The reaction mixture was maintained at 0° C. for 2 h, and then allowed to warm to room temperature overnight. Purification by flash chromatography on a silica gel column using (10-20%) ethyl acetate/hexanes as the eluant gave of 2(R)-(4-methoxybenzenesulfonylamino)-3-methylbutyric acid tert-butyl ester (18 g) as a white crystalline solid.

Workup

  1. customcan be prepared by the procedure
  2. temperatureto warm to room temperature overnight
  3. customPurification by flash chromatography on a silica gel column

Sources & evidence

ORD record
ord-380cca9a3228476bb6f43fafadb5936a
Source dataset
uspto-grants-2002_12
Patent number
US06492394B1

Reaction notes

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