5545-54-0Relevant articles and documents
A N-(9-fluorenylmethyloxycarbonyl)-O-tert-butyl-L-tyrosine method for the preparation of
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Paragraph 0045; 0048, (2017/04/11)
The invention relates to a method for preparing N-(9-fluorenylmethoxy carbony)-O-tertiary butyl-L-tyrosine. The problem that an enantiomer is easily generated is solved. The method comprises the following synthetic steps: (1) dissolving L-Tyr into a methanol solution, adding SOCl2 and then carrying out reflux reaction, so as to obtain Tyr-OMe.HCl; (2) dissolving the Tyr-OMe.HCl into a water solution, adding AcOEt and Na2CO3 and then reacting with Z-Cl, and controlling the pH of the system at 7-10, so as to obtain Z-L-Tyr-OMe; (3) dissolving the Z-L-Tyr-OMe into a CH2Cl2 solution, adding H2SO4 and isobutene, reacting at normal temperature for 1-10 days, so as to obtain Z-L-Tyr(tBu)-OMe; (4) adding the NaOH solution to the Z-L-Tyr(tBu)-OMe to react, so as to obtain Z-L-Tyr(tBu); (5) dissolving the Z-L-Tyr(tBu) into methanol, adding Pd/C, and leading in hydrogen to react, so as to obtain L-Tyr(tBu); (6) dissolving Z-L-Tyr(tBu) into the water solution, adding the Na2CO3 and THF and then reacting with Fmoc-osu, and controlling the pH of the system at 8-10, so as to obtain Fmoc-Tyr(tBu). By adopting the method, generation of the enantiomer is avoided, and the citric acid is taken as an acidifier, so that the product is more stable, and the reaction processes do not relate to high-temperature and high-pressure reaction, and the method is applicable to large-scale production.
N,N-dialkylated leucine enkephalins as potential δ opioid receptor antagonists
Lovett,Portoghese
, p. 1144 - 1149 (2007/10/02)
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