ORGANIC PHOSPHORUS COMPOUNDS 87¹: SOME REACTIONS OF 0-ETHYL-2-CHLOROETHYLPHOSPHONITE

Abstract

Primary and secondary amines react with O-ethyl-2-chloroethylphosphonite with the formation of 2-substituted aminoethylphosphonites, RR′NCH₂CH₂P(O)(OC₂H₅)H, 1. The reaction very likely proceeds through the intermediate formation of O-ethyl-vinylphosphonite. Hydrolysis of 1 produces the hydrochlorides of 2-substituted aminoethylphosphonous acids, RR′NCH₂CH₂PO₂H₂ 2. These compounds interact with formaldehyde and benzylglycine to give the phosphinic acid derviatives 3, RR′NCH₂CH₂P(O)(OH)CH₂N(CH₂C₆Hs)CH₆CO₂H, which upon debenzylation produce N-(2-substituted aminoethylphosphinylmethyl) glycines 4, RR′NCH₂CH₂P(O)(OH)CH₂NHCH₂C0₂H. The Mannich type reaction can also be performed with the half-esters 1 and with the acylated compounds 5a or 5b. This type of reaction has been used to prepare 2-aminoethyl-aminomethylphosphinic acid, H₂NCH₂CH₂P(O)(OH)CH₂NH₂ 8. Likewise, addition of acrylonitrile to 5b, followed by hydrogenation, hydrolysis and debenzylation gives 2-aminoethyl-3-aminopropylphosphinic acid, 12 H₂NCH₂CH₂P(O)(OH)CH₂CH₂CH₂NH₂. Interaction of If with a substituted 3,4-dinitrodiphenylether yields a phosphonite half-ester 13 which upon hydrolysis gives the acid 14. Both these compounds exhibit herbicidal activity.

Key Words:

• O-Ethyl-2-chloroethylphosphonite; subst.
• aminoethylphosphonites; subst.
• aminoethylphosphonous acids
• Mannich reaction
• 2-aminoethyl-aminomethylphosphinic acid
• 2-aminoethyl-3-aminopropylphosphinic acid.