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

. 2021 Oct 30;14(11):1109. doi: 10.3390/ph14111109

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

© 2021 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 (https://creativecommons.org/licenses/by/4.0/).

PMC Copyright notice

Preparation of compounds 17–22. Reagents and conditions: (a) tert-butyl-piperazine, K₂CO₃, DMSO, 80 °C, 72 h; (b) trifluoroacetic acid, CH₂Cl₂, rt, 24 h; (c) triethylamine, acetyl chloride, acetonitrile, rt, 24 h (compound 30) or (1) triethylamine, CH₂Cl₂, 0 °C, 5 min; (2) pivaloyl chloride, rt, 24 h (compound 31) or (1) Na, EtOH, rt; (2) EtOH, 50 °C, 15 min; (3) CHCl₃, 50 °C, 30 min (compound 32) or 1N HCl, 2N KOH, potassium cyanate, rt, 2 h (compound 33) or (1) triethylamine, 1,1′-carbonyldiimidazole, rt, 30 min; (2) dimethylamine hydrochloride 80 °C, 6 h (compound 34); (d) 15% (m/m) palladium on activated carbon, H₂, MeOH, rt, 24 h; (e) (1) carboxylic acid 2, CH₂Cl₂, 0 °C, 5 min; (2) 2-chloro-N-methylpyridinium iodide, DIPEA, rt, 24 h.