New method for the synthesis of 1-aminoalkyl-phosphonic and phosphinic acids Communication 4. Synthesis of (1-aminoalkyl)phenylphosphinic acids

Summary

• 1. The reaction between monoesters of phenylphosphonous acid, ketones or aldehydes, and ammonia has been studied. (1-Amino-1-methylethyl)-, (1-amino-1-methylpropyl)- (a-aminobenzyl)-, and (1-aminocyclohexyl)-phenylphosphinic acids have been prepared, and also the hydrochlorides of their ethyl esters.

• 2. With (1-amino-1-methylethyl)phenylphosphinic acid as working example, the structure of the synthesized compounds has been proved, (1-Amino-1-methylethyl)phenylphosphinic acid can be converted in the usual way into its acetyl derivatives, and treatment with nitrous acid converts it into the correspnding hydroxy acid.

• 3. A mechanism has been proposed for the reaction: it is considered that the alkyl hydrogen phenylphosphonite ionized under the influence of ammnia and its anion then adds to the carbonyl compound; this is followed by replacement of the hydroxy group by amino.