Organic compounds -- part of the class 532-570 series – Organic compounds – Amino nitrogen containing
Patent
1987-02-09
1990-04-17
Lee, Mary C.
Organic compounds -- part of the class 532-570 series
Organic compounds
Amino nitrogen containing
C07C12722
Patent
active
049182277
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a novel process for the preparation of benzoyl ureas, which are useful as pesticides.
THE PRIOR ART
It is known to prepare benzoyl ureas by reacting a corresponding benzoic acid amide with a substituted phenylisocyanate. The isocyanate starting compound may be prepared from a corresponding aniline by reaction with phosgene. The aniline itself may be obtained from the corresponding nitro compound by reduction.
DESCRIPTION OF THE INVENTION
We have discovered that there is a new reaction sequence which provides a technically simple method of preparing benzoyl ureas of the formula ##STR2## wherein X is hydrogen, fluorine or chlorine; ##STR3## where R.sub.1, R.sub.2 and R.sub.4 are each independently fluorine, chlorine, bromine, CF.sub.3, OCF.sub.3 or hydrogen; ethoxy substituted by four to five fluorine and/or chlorine atoms, phenyl which is mono- or polysubstituted by fluorine, chlorine, bromine, CH.sub.3, CF.sub.3, OCF.sub.3, OCF.sub.2 CHF.sub.2 OC.sub.2 F.sub.5, NO.sub.2 or CN; or pyridyloxy which is mono- or polysubstituted by fluorine, chlorine or CF.sub.3 ; or R.sub.2 and R.sub.3 or R.sub.3 and R.sub.4, together with each other, are --O--CF.sub.2 --CF.sub.2 --O--.
X and Y are preferably the pairs F/H, F/F, Cl/H, Cl/Cl or Cl/F. Examples of Q are:
The various substituents may be identical or different within the scope of the above definition. Alkyl groups may be straight-chained or branched. In the case of polysubstitution, CN, CF.sub.3, OCF.sub.3, OC.sub.2 F.sub.5, OCF.sub.2 --CF.sub.2 H occur only once, whereas halogen atoms, either identical or different, may occur up to six times.
The process according to the invention proceeds through the following stages: ##STR4##
In formula (II) Z is a substituent which may be replaced by the azide ion.
Examples includes: fluorine, chlorine, bromine, iodine and groups of the formula O--R.sub.6 wherein R.sub.6 is lower alkyl, phenyl, benzyl, lower alkoxycarbonyl, phenoxycarbonyl, lower alkylcarbonyl or benzoyl.
The halogens fluorine and chlorine are preferred.
Lower alkyl radicals are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec.butyl and tert.butyl.
Examples of azides include sodium azide, potassium azide and calcium azide.
The steps may be carried out one after the other in the same reaction medium without isolation of the intermediate products. Steps 1 and 2 are carried out at temperatures between about 80.degree. C. and the boiling point of the reaction mixture, taking care to avoid temperatures above 180.degree. C. The range between about 100.degree. and 140.degree. C. is preferred. The reaction constitutes thermal degradation of a carboxylic acid via the carboxylic acid azide to yield the isocyanate by Curtius degradation. Decomposition of the azide is effected so that no substantial quantities thereof remain in the reaction mixture. Suitable solvents include, in particular, halogenated benzenes, such as chlorobenzene, dichlorobenzene and high-boiling-point ethers, and also aromatic hydrocarbons such as toluene.
Further reaction of the isocyanate with the amide V is carried out by adding the amide V to the solution of the isocyanate and stirring the mixture at temperatures between about 80.degree. and 160.degree. C., preferably between 90.degree. and 130.degree. C. Depending on the reactivity of the components and the reaction temperature, the reaction time is up to several hours.
The method of synthesis according to the present invention via the compounds III, which have heretofore not been described, makes it possible to avoid the highly undesirable reaction with phosgene (VIII).
The compounds of the formula I are obtained with good yields and high purity without isolation of the intermediate in the individual steps.
Examples of the compounds which may advantageously be prepared according to the invention are the compounds disclosed in German Offenlegungsschriften 23 23 236, 25 04 982, 25 97 944, 25 31 279, 25 37 413, 26 01 780, 27 26 684, 30 03 112, 30 26 825, 30 41 947, 32 23 505, 32 32 265 and 32 35 419 and in pu
REFERENCES:
patent: 4005223 (1977-01-01), Sirrenberg et al.
patent: 4085226 (1978-04-01), Sirrenberg et al.
Methoden der Organischen Chemie, vol. E4, Kohlensaure-Denivate, 1983, George Thieme Verlag, pp. 763-764.
Becher Heinz M.
Mengel Rudolf
Ost Walter
Lee Mary C.
Northington-Davis Zinna
Shell Internationale Research Naatschappy B.V.
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