Hydrochloric Acid → 2(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonylamino)-3-methylbutyric acid benzyl ester

HRID 2297968Notes

Reaction equation

HRID 2297968 reaction equation
[CH2:1]([O:8][C:9](=[O:15])[C@@H:10]([CH:12]([CH3:14])[CH3:13])[NH2:11])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C[Si](C#N)(C)C.[CH3:22][O:23][C:24]1[CH:29]=[C:28]([CH3:30])[C:27]([S:31](Cl)(=[O:33])=[O:32])=[C:26]([CH3:35])[C:25]=1[CH3:36].Cl>C(#N)C.C(OCC)(=O)C>[CH2:1]([O:8][C:9](=[O:15])[C@H:10]([NH:11][S:31]([C:27]1[C:28]([CH3:30])=[CH:29][C:24]([O:23][CH3:22])=[C:25]([CH3:36])[C:26]=1[CH3:35])(=[O:33])=[O:32])[CH:12]([CH3:13])[CH3:14])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 82115Trimethylsilyl cyanideHCID 5627874-Methoxy-2,3,6-trimethylbenzenesulfonyl chlorideHCID 7350007Benzyl D-valinate

Product 1

HCID 114869322(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonylamino)-3-methylbutyric acid benzyl esterYield 98.8%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of D-valine benzyl ester (4 g, 19.3 mmol) and trimethylsilylcyanide (7.2 mL, 57.9 mmol) in acetonitrile (40 mL) was added 4-methoxy-2,3,6-trimethylbenzenesulfonyl chloride (4.8 g, 19.3 mmol). After 3 h, the reaction mixture was diluted with ethyl acetate (100 mL) and transferred to a separatory funnel. Aqueous hydrochloric acid (120 mL, 2.5%) was added and the organic layer was separated and washed with 5% sodium bicarbonate and brine and then dried over magnesium sulfate. The organics were removed in vacuo to give 2(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonylamino)-3-methylbutyric acid benzyl ester (8 g) as a brown oil.

Workup

  1. customtransferred to a separatory funnel
  2. customthe organic layer was separated
  3. washwashed with 5% sodium bicarbonate and brine
  4. dry with materialdried over magnesium sulfate
  5. customThe organics were removed in vacuo

Sources & evidence

ORD record
ord-14f9cefec8ce48bfb98a9386196029a8
Source dataset
uspto-grants-2002_12
Patent number
US06492394B1

Reaction notes

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