Carboxyalkyl esters of N-phosphonomethyl glycine and their salts and a process for their preparation are described. These esters and salts are useful as contact herbicides.
Hydroxyalkyl esters of N-phosphonomethyl glycine and their salts and a process for their preparation are described. These esters and salts are useful as contact herbicides.
Novel compounds represented by formula (I) or (II) are provided: ##STR1## They can control annual and perennial weeds, shrubs and aquatic plants more effectively than their mother compounds, or (2-amino-4-methylphosphinobutyryl)alanylalanine and 2-amino-4-methylphosphinobutanoic acid, respectively.
A known antibiotic, SF-1293 substance and salts thereof have now been found to exhibit high herbicidal effects against a wide variety of herbaceous and woody plants, but they are non-phytotoxic particularly to a useful woody plant, Chamaecyparis obtusa. The herbicidal effects of these SF-1293 substances can be noticeably enhanced by applying in combination with certain known herbicides or compounds having biological activities.
The invention relates to an N-sulfomethylglycinate of formula: COOR.sub.1 being a hydrolysable carboxylic ester group. It also relates to a process for the preparation of the compound of formula (I) consisting in putting in contact sulfur dioxide, formaldehyde, and glycine in the presence of a R.sub.1 OH alcohol, or glycinate. It also relates to the use of the compound of formula (I) for the preparation of herbicides of the glyphosate type of reaction with a phosphite or a phosphonate of formula (R.sub.2 O).sub.2 P(O) H in which (R.sub.2 O).sub.2 P is a hydrolysable phosphonic ester group, then optionally by a subsequent hydrolysis reaction.
