. 2019 Apr 4;24(7):1332. doi: 10.3390/molecules24071332
© 2019 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/).
Scheme 1.
The synthesis of the target compound 3a–m.