An Efficient Synthesis of 3,5-Bis-Aminated Pyrazolo[1,5-a]Pyrimidines: Microwave-Assisted Copper Catalyzed C-3 Amination of 5-Amino-3-Bromo-Substituted Precursors

Molecules, Journal Year: 2025, Volume and Issue: 30(3), P. 458 - 458

Published: Jan. 21, 2025

An efficient method has been developed for the rapid production of diverse arrays 3,5-bis-aminated pyrazolo[1,5-a]pyrimidines. The utilizes CuI (5 mol%) and carbazole-based ligand L-1 (N-(9H-carbazol-9-yl)-1H-pyrrole-2-carboxamide) (10 Ullmann-type coupling various amines to 5-amino-3-bromopyrazolo[1,5-a]pyrimidine precursors after heating in diethylene glycol (DEG) only 1 h at 80 °C (microwave heating). 3,5-Bis-aminated products were obtained good excellent yields (60–93%, 83% average 29 examples). 1° 2° alkylamines, as well a variety aryl- or heteroarylamines coupled efficiently, alkyl (or aryl) C-5 tolerated. optimized conditions worked on both 50 mg 1.0 g scales gave two steps from commercially available 3-bromo-5-chloropyrazolo[1,5-a]pyrimidine. Advantages provided by this include short reaction time, yields, broad substrate scope, avoidance toxic reagents commonly utilized reductive aminations C-3 NH2 substituted precursors.

Language: Английский

Copper-Catalyzed One-Pot Protocol for Reductive N-Arylation of Nitroarenes with (Hetero)aryl Chlorides in Water

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 9, 2024

A novel protocol for the Cu-catalyzed reductive

Language: Английский