Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2020 Mar 13;25(6):1313. doi: 10.3390/molecules25061313

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2020 by the authors.

Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

PMC Copyright notice

Scheme 4 — Oxidation of 10 with; 1,3,5-trichloro-2,4,6-triazinetrione (trichloroisocyanuric acid, TCCA)/ (2,2,6,6-tetramethylpiperidi-1-yl)oxyl (TEMPO): preparation of Fmoc-l-Dap(Ts)-OCH₃ (14) Experimental conditions: Step 1 (acydolysis), Trifluoroacetic acid (TFA)/Trifluoroethanol (TFE)/DCM, 15 min, r.t. (quantitative yield); Step 2 (oxidation), TCCA/TEMPO/NaBr/aq. NaHCO₃/Acetone, 20 min. at 0 °C, then overnight, r.t.; Step 3 (methylation), 0.66 N CH₂N₂ in DCM, 15 min, r.t. (14, yields: 92% over 2 steps, and 68% referred to the initial amount of 1).