Convergent Versus Divergent Three-Step Synthesis of the First (4-Aminophenoxy)alkanoic Acid–Based Tripodal Melamines

Abstract

Starting from N-(4-hydroxyphenyl)acetamide (Paracetamol, convergent approach) or from cyanuric chloride in reaction with 4-aminophenol (divergent approach), two synthetic routes toward novel tripodal N-substituted melamines as s-triazine derivatives of (4-aminophenoxy)acetic acid or of 4-(4-aminophenoxy)butyric acid are comparatively defined. The key steps consist of Williamson etherification of N-masked forms of 4-aminophenol and acidic hydrolysis of the N- and/or O-protected (4-aminophenoxy)alkanoic segments.

GRAPHICAL ABSTRACT

Keywords:

• (4-Aminophenoxy)acetic acid
• 4-(4-aminophenoxy)butyric acid
• melamine
• Williamson etherification

SUPPLEMENTAL MATERIAL

Typical) procedures for preparations of compounds 2a, 2b, 3a, 3b, 4a, and 4b (convergent route) and A, B, and 5 (divergent route); full analytical data of compounds A, 2a, 2b, 3a, 3b, 4a, 4b, 5a, and 6b; ¹H NMR monitoring of acidic hydrolysis of compound 2b; ¹H and ¹³C NMR spectra of compounds 2a, 2b, 3a, 3b, 4a, 4b, A, B, 5, 6a, and 6b; and MS of compounds A and B for this article can be accessed on the publisher’s website.