Patent GB-1093228-A (GB)
Title: Substituted pyridyl ureas and processes for their preparation
IPC: C07D213/79
Filed: 1965-08-24
Abstract: Novel compounds of formula <FORM:1093228/C2/1> in which R1 and R2 represent a halogen atom, an alkyl group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms, an amino group which may be acylated by carboxylic acids having 1-6 carbon atoms or carbonic acids, or a carbamoyl group, and wherein R2 may also represent a hydrogen atom, R3 and R4 represent a hydrogen atom, an alkyl group having 1-6 carbon atoms or a phenyl group, and R5 represents a hydrogen atom or an alkyl group having 1-6 carbon atoms, are prepared (a) by reacting an amine of Formula II <FORM:1093228/C2/2> (1) with an isocyanate of formula R3NCO in molar quantities in the presence of a solvent at a temperature of 0 DEG  to 100 DEG  C.; (2) with a carbamic acid halide of formula HalOCNR3R4 either in molar quantities in the presence of an acid binding agent, or using 2 mols. of amine per mol. of acid halide, in the presence of a solvent at a temperature of 0 DEG  to 180 DEG  C.; (3) with a carbamic acid ester of formula R6O-OCNR3R4 in which R6 represents an alkyl radical having 1-4 carbon atoms, or a phenyl or benzyl radical, optionally in the presence of a solvent, at a temperature of from 0 DEG  to 200 DEG C.; (4) with molar quantities of phosgene and an amine HNR3R4 in the presence of 2 mols. of an acid-binding agent per mol. of phosgene at a temperature of from - 20 DEG  to 100 DEG  C. optionally in the presence of a solvent; (5) with a carbonic acid ester and an amine of formula HNR3R4 in molar quantities, optionally in the presence of a solvent, at a temperature of 0 DEG  to 250 DEG  C.; (6) when R3 and R4 are both methyl, with N,N1-dimethylnitroso-urea in molar quantities in the presence of a solvent at a temperature of 0 DEG  to 100 DEG  C.; or (7) with a compound of formula R7-NH-CONR3R4 in which R7 is an acyl group, preferably an acetyl group, or a nitro group, in molar quantities or with an excess of compound R7-NHCONR3R4 optionally in the presence of a solvent, preferably at a temperature of 0 DEG  to 200 DEG  C.; (b) by reacting a pyridine isocyanate with an amine of formula HNR3R4 in molar quantities in the presence of a solvent at a temperature of 0 DEG  to 100 DEG  C.; (c) by reacting a compound of Formula II in which the -NHR5 group is replaced with an -N(R5)COOR6 group with an amine of formula HNR3R4 optionally in the presence of a solvent, at a temperature of 0 DEG  to 200 DEG  C.; (d) by reacting a compound of Formula II in which the -NHR5 group is replaced with an -N(R5)-CS-NR3R4 group with an oxidizing agent to replace the sulphur atom by an oxygen atom; (e) where R3 and R4 are both hydrogen atoms and R5 is an alkyl radical, by reacting an aniline with excess quantities of a compound of formula R5HN-CO-NH2 at a temperature of 0 DEG  to 200 DEG  C. optionally in the presence of an inert solvent; (f) by reacting a compound of Formula I in which R3 is hydrogen and R4 is a hydrogen atom, or an acyl group, preferably an acetyl group, with an amine of formula HNR3R4 optionally in the presence of a solvent, preferably at a temperature of 0 DEG  to 200 DEG  C.; (g) by chlorinating or brominating a compound of Formula I in which R1 is hydrogen preferably in the presence of a solvent and preferably at a temperature of 0 DEG  to 100 DEG  C.; (h) when R3 and R4 are hydrogen or alkyl groups and R5 is an alkyl group, by alkylating a compound of Formula I in which R3, R4 and R5 are hydrogen; and (i) when R1 and/or R2 are acylamino groups, by acylating the corresponding amino derivatives with carboxylic acids having 1 to 6 carbon atoms, or carbonic acids.