Polyethylene Glycol as a Green Medium for the Microwave-Assisted Synthesis of Guanamines

The hazardous, toxic, and flammable solvents, methyl and ethyl cellosolves (2-methoxy- and 2-ethoxyethanols), are typically used as media for the synthesis of guanamines (1,3,5-triazine-2,4-diamines). We found that these problematic solvents can be efficiently replaced by a green alternative, polyethylene glycol 400 (PEG 400). The reaction efficiency in PEG 400 media was further improved by applying focused microwave irradiation. The method scope is illustrated by the preparation of twenty diverse 1,3,5-triazine-2,4-diamines.

Automated summary

In this study, the hazardous and toxic solvents, methyl and ethyl cellosolves, commonly used in the synthesis of guanamines, were efficiently replaced by a green alternative, PEG 400. Additionally, the reaction efficiency of PEG 400 was improved by using focused microwave irradiation. The method was successfully applied to the synthesis of twenty diverse 1,3,5-triazine-2,4-diamines.