Sodium Hydroxide → 4-[(Tert-butoxy)carbonyl]piperazine-2-carboxylic acid

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Reaction Steps

piperazine-2-carboxylic acid dihydrochloride (10.0 g, 49.23 mmol) is dissolved in 1:1 dioxane/water (320 ml). 50% Aqueous sodium hydroxide is added to bring the pH to 11. BOC-ON (2-(tert-butoxycarbonyloxyimino)-2-phenylacetonitrile), (15.59 g, 63.32 mmol) is dissolved in dioxane (80 ml) and added dropwise while maintaining the pH at 11 with 50% aqueous sodium hydroxide. The reaction is stirred overnight at ambient temperature. The reaction mixture is then extracted with diethyl ether (5×250 ml) and acidified to pH 2 with concentrated hydrochloric acid. The di-Boc compound is then extracted out with ethyl acetate (4×200 ml) and the acidic aqueous solution containing the desired mono-Boc product is then taken on in the synthesis.

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