Patent GB-789445-A (GB)
Title: Carboxy-alkyl n-substituted phenyl carbamate and herbicidal compositions thereof
IPC: C07C271/06
Filed: 1954-05-26
Abstract: The invention comprises compounds having the formula: <FORM:0789445/IV (b)/1> wherein R is an alkylene or halogenated alkylene group, X is a hydrogen atom or an alkyl, cycloalkyl or phenyl group, Y is a halogen atom or an alkyl, alkoxy, cyano or nitro group, and n is 1-5, and esters, salts or amides thereof, Y also being hydrogen in the case of the aralkyl esters.  The compounds are used in herbicidal compositions (see Group VI).  The compounds are prepared by reacting a phenyl isocyanate with an ester of an hydroxy-aliphatic carboxylic acid, whereby compounds of the above formula wherein X is hydrogen are prepared, or by reaction of a phenyl amine, having at least one hydrogen atom linked to its nitrogen atom, with the haloformate of an ester of an hydroxy-aliphatic carboxylic acid.  The phenyl isocyanates are prepared by reacting a phenyl amine with a carbonyl halide, preferably phosgene.  The haloformates are prepared by reacting a carbonyl halide, such as phosgene or carbonyl bromide, with an hydroxy-aliphatic carboxylic acid ester, preferably by the method described in Specification 624,604.  The free acids may be obtained from the ester products by hydrolysis and may be converted into salts of metals such as lithium, sodium, potassium, rubidium, caesium, strontium and barium, or salts of ammonia and amines such as mono- or tri-methylamine, diethylamine, mono- or triethanolamine and isopropanolamine.  The amides are prepared by ammonolysis of the esters in known manner.  Specified acids, which in the form of their esters may be used in the process of the invention, are glycollic, lactic, a -or b - or g -hydroxybutyric, a -hydroxy-b -chlorobutyric, b -chloro-lactic, acetonic, hydroxycaproic acids such as leucic, a -hydroxy-valeric, a - or b -hydroxy-isovaleric, a -hydroxy-caprylic, tetramethyl-hydracrylic and hydroxy-stearic acids.  Specified esters are esters of lactic acid with alcohols having 1-30 carbon atoms, cyclohexyl lactate, benzyl lactate, 2-chloroethyl lactate, methyl and ethyl glycollates and ethyl a  - hydroxy - isobutyrate. Specified primary amines are chloroanilines having 1-5 chlorine atoms and the corresponding bromine, fluorine and iodine compounds, mixed haloanilines such as chlorofluoroanilines, methylanilines having 1-5 methyl groups, ethyl- or propyl- or isopropyl-anilines, 4-methyl-5-ethylaniline, aminoanisoles, 2 : 5-dimethoxyaniline, polymethoxyanilines, 4 - amino - 3 - chloro - toluene, 2-amino - 4 - chlorotoluene and 2 - chloro - 5-methoxy-aniline.  Specified secondary amines are diphenylamine and N-methyl-, ethyl-, propyl- or butyl-aniline.  The secondary amines must be substituted in the nucleus as specified above except when the aryl esters are prepared. In examples: (1) m-chloroaniline was reacted in benzene solution with alpha-carbobutoxyethyl chloroformate to give alpha-carbobutoxyethyl 3-chlorophenylcarbamate which was hydrolysed with aqueous sodium hydroxide to give alpha-carboxyethyl 3-chlorophenyl carbamate; (2) 3-nitro- or methyl-phenyl isocyanate was reacted with n-butyl lactate to give alphacarbobutoxyethyl-3-nitro- or methylphenylcarbamate; (3) phenyl isocyanate and benzyl lactate were reacted to give alpha-carbobenzoxy-ethyl phenyl carbamate; (4) m-aminobenzonitrile or p-cresidine was reacted with alpha-carbobutoxyethyl chloroformate to give alpha-carbobutoxyethyl 3 - cyanophenyl - or 2 - methoxy-5-methylphenyl-carbamate.ALSO:Herbicidal compositions comprise compounds having the formula <FORM:0789445/VI/1> wherein R is an alkylene or halogenated alkylene group, X is a hydrogen atom or an alkyl, cycloalkyl or phenyl group, Y is a halogen atom or an alkyl, alkoxy, cyano or nitro group and n is 1-5, and esters, salts and amides thereof, Y also being hydrogen in the case of the aralkyl esters (see Group IV (b), dissolved in an inert solvent or dispersed in a solid carrier.  Specified solvents are xylene, toluene, gasoline, kerosine, methanol, ethanol, ethers and ketones.  Certain of the salts are water-soluble.  Inorganic silicates are specified as solid carriers.  Specification 624,604, [Group IV (b)], is referred to.