. 2017 May 12;22(5):785. doi: 10.3390/molecules22050785
© 2017 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 target compounds 7a–7r.