Sodium Hydroxide → N-(Methoxycarbonyl)-L-tert-leucine
Reaction equation
[NH2:1][C@H:2]([C:7]([OH:9])=[O:8])[C:3]([CH3:6])([CH3:5])[CH3:4].[OH-:10].[Na+].O1C[CH2:16][O:15][CH2:14]C1>>[CH3:14][O:15][C:16]([NH:1][C@H:2]([C:7]([OH:9])=[O:8])[C:3]([CH3:6])([CH3:5])[CH3:4])=[O:10]Participants
Conditions
- Temperature
- 60 °C
Procedure
23.5 ml (305 mmol) of methyl chlorotormate are added, over a period of 20 min, to a solution of 20 g (152 mmol) of (L)-tert-leucine (=2(S)-amino-3,3-dimethylbutyric acid=(L)-α-tert-butylglycine; Fluka, Buchs, Switzerland) in a mixture of 252 ml (504 mmol) of a 2N aqueous solution of sodium hydroxide and 80 ml of dioxane, and the reaction solution is heated at 60° C. for 14 h. After the reaction solution has cooled down to room temperature, it is washed twice with methylene chloride. The aqueous phase is acidified to pH 2 with 4N aqueous hydrochloric acid and extracted three times with ethyl acetate. The organic extracts are combined, dried (Na2SO4) and concentrated by evaporation. During this procedure, the product begins to harden. Digestion of the hardened solid with hexane yields the title compound as a white powder. M.p. 106-108° C.
Workup
- temperatureAfter the reaction solution has cooled down to room temperature
- washit is washed twice with methylene chloride
- extractionextracted three times with ethyl acetate
- dry with materialdried (Na2SO4)
- concentrationconcentrated by evaporation
Sources & evidence
- ORD record
- ord-b0e2709506da4e4fb8054dd32a08e602
- Source dataset
- uspto-grants-2002_09
- Patent number
- US06451973B1
Reaction notes
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