L-Threonine → HCID 178462331, compound

HRID 1156737Notes

Reaction equation

HRID 1156737 reaction equation
[NH2:1][C@H:2]([C:6]([OH:8])=O)[C@@H:3]([CH3:5])[OH:4].[OH-].[Na+].[N+:11]([C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=1SCl)([O-:13])=[O:12].[S:22](=O)(=O)(O)[O-].[K+]>O.O1CCOCC1>[N+:11]([C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=1[NH:1][C@H:2]([C:6]([OH:8])=[S:22])[C@@H:3]([CH3:5])[OH:4])([O-:13])=[O:12]

Participants

7

Reactant 4

HCID 6288L-ThreonineHCID 14798Sodium Hydroxide2×HCID 243192-Nitrobenzenesulfenyl chlorideHCID 516920Potassium bisulfate

Product 1

HCID 178462331HCID 178462331, compound

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

L-threonine (11.9 g) is added to dioxane (125 ml) and 2 N sodium hydroxide (50 ml). To the vigorously stirred solution, o-nitrophenylsulfenyl chloride (20.9 g) is added in ten equal portions over fifteen minutes, while 2 N sodium hydroxide (60 ml) is slowly added dropwise. After five more minutes the reaction mixture is diluted with water (400 ml) and acidified to pH 2.5 with 10% potassium bisulfate. The organic layer is immediately extracted with ethyl acetate (three 200 ml portions), and the combined extracts are dried over sodium sulfate, and then concentrated to an oil. The product crystallizes on scratching (20.0 g). Recrystallization of 17 g from acetone/hexane affords 9.5 g of crystals, melting point 145°-148° C. which are stored in a freezer and used promptly.

Workup

  1. additionis slowly added dropwise
  2. extractionThe organic layer is immediately extracted with ethyl acetate (three 200 ml portions)
  3. dry with materialthe combined extracts are dried over sodium sulfate
  4. concentrationconcentrated to an oil
  5. customThe product crystallizes
  6. customRecrystallization of 17 g from acetone/hexane

Sources & evidence

ORD record
ord-74528a0c42be458e805760f7e6115f62
Source dataset
uspto-grants-1982_06
Patent number
US04337197

Reaction notes

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