Citric Acid → 4-(((Tert-butoxy)carbonyl)amino)cyclohexane-1-carboxylic acid

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Reaction Steps

To a solution of 2.86 g (20 mmol) of 4-aminocyclohexane carboxylic acid in 40 mL of 0.5M aqueous NaOH solution, 20 mL of dioxane and 4 mL of acetonitrile was added a total of 6.5 g (30 mmol) of tBoc anhydride at room temperature. After 20 h, 100 mL of ethyl acetate and 100 mL of 10% aqueous citric acid solution were introduced. The aqueous layer which formed was separated and extracted with three-50 mL portions of ethyl acetate. The organic phases were combined, dried (sodium sulfate) and concentrated in vacuo to give 6.0 g (125%) of crude 4-(t-butoxycarbonylamino)cyclohexane carboxylic acid as a colorless oil which solidified upon standing.

Provenance & Evidence