N-Carbobenzoxy-L-proline

A soln. of N-trifluoroacetylimidazole in dry tetrahydrofuran added at 0° to a soln. of N-carbohenzoxy-L-proline and p-nitrophenol in the same solvent, kept an additional hr. at 0°, then stirred 4 hrs. at room temp. N-carbobenzoxy-L-proline p-nitrophenyl ester. Y 78.5%. — In general, the use of 1-acylimidazoles seems less satisfactory then available alternatives, but may be useful in some specific instances. F. e. s. H. D. Law, Soc. 1965, 3897. 

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