α-FUNCTIONAL CYCLOALKYLPHOSPHONATES. II. SYNTHESIS OF α-AMINOMETHYL AND α-(N-SUBSTITUTED)-AMINOMETHYLCYCLOALKYLPHOSPHONATES

Abstract

α-Aminomethylcycloalkylphosphonates 8 (n=2 to 5) were prepared by catalytic hydrogenation of the corresponding α-cyanoalkylphosphonates 5. The N-alkylation of 8 was realized through a metalation-alkylation sequence of their N-phosphorylated derivatives, while the carbethoxymethyl substituent was directly introduced on the primary amino groups. Finally, the various protective groups (phosphonic esters, phosphoramidates and carboxylic esters) were overall liberated by hydrolysis in concentrated HCl, leading to the corresponding α-aminomethyl-, α-(N-alkylated)-aminomethyl-. and α-(N-carboxy-methylated)-aminomethylcycloalkylphosphonic acids 6, 7-A and 7-B, respectively.

Key Words:

• Cycloalkylphosphonates
• aminophosphonates
• phosphoramidates
• aminophosphonic acids
• (N-substituted)-aminophosphonic acids