Synthesis of Chemical Compounds. Results, Discussion and Experimental Section

Internship Report from the year 2015 in the subject Chemistry - Organic Chemistry, grade: 1,3, University of Cologne (Institut für Organische Chemie), language: English, abstract: A literature survey via Reaxys revealed 2 references in which this compound was described as the product. The first synthesis has been published by Corey in the Journal of Organic Chemistry in 1988: N-(benzyloxycarbonyl)-(S)-proline (3) was synthesized in 75.2% yield from proline by reaction with benzyl chloroformate in an aqueous solution at 0-5°C. E. J. Corey, J. Org. Chem., Vol. 53, No. 12, 1988, 2861-2863 seemed to be the best choice for its high yield.

The protection of proline with benzylchloroformate gave a colourless solid, which recrystallized from petrolium ether. The yield of 75.2% is below that reportedin the literature (96%). The purity of the product could not be proofed, since no enough analytic data are available. For the product (3) no GC-MS was recorded, because of its carbon acid group that might damage the mass spectrometry system.

The hydroxide ion of NaOH deprotonates the NH-group of proline to form water and the electron pair of the nitrogen anion undergo a nucleophilic attack to the carbon atom of the carbonyl-group to give (3). The sodium cation forms with chloride anion sodiumchloride that prcipitates. An example for the application of the cyclic amino acid is its use as a pharmaceutical intermidiate, which is used for the synthesis of Eletriptan, a drug for the treatment of migriane.