DD291081A5 - PROCESS FOR PREPARING 1,2,3,4-TETRAHYDRO-2,4-DIOXO-CHINAZOLIN-3-YL-ALKANSAEUREESTERS - Google Patents

Abstract

The invention relates to a process for the preparation of * according to the invention a * in solution or in suspension in an organic solvent or without solvent with water to a * of the general formula II is implemented. Among the compounds of general formula II are fungicidal or plant growth regulatory substances. Formula II {* *}

Description

For this 1 page formulas

Field of application of the invention

The invention relates to a process for the preparation of I ^ .S ^ -Tetrahydro ^ -dioxo-quinazolin-S-yl-alkanoic acid esters of the general formula II. The invention is for agriculture, gardening and forestry of interest, where compounds prepared according to the invention z. B. can be used as fungicides or plant growth regulators.

Characteristic of the known state of the art

A large number of quinazolines with potential action as phyto-effectors, fungicides, acaricides, insecticides or herbicides are known (M.Suess, S.Johne, Z. Chem., 1961 (1981)).

Of the compounds of the general formula II, some representatives are already known. Starting from the quinazoline-2,40H, 3H) -dione, after its salt formation with ethyl bromoacetate, the 1: 1-metahydroxyethyl-1,5-dioxo-quinazolin-S-ethylacetate (II: η = O, X = CH ₂ , R ² = C ₂ H ₆ ) (M.Suess, S.Johne, B.Hillmann, DDR-PS 232269) or with 4-Brombutyronitnl in mixture among other compounds, the corresponding Quinazolindionnitril prepared, the hydrolysis of the corresponding butanoic acid and by esterification of 4- ( 1 ^, S, -tetrahydro-JM-dioxo-quinazolin-S-yl) -butanoic acid ethyl ester (II: η = 0, X = CH ₂ CH ₂ CH ₂ , R ² = C ₂ H ₆ ) gave (LRCrook, ABAJansen, KEVSpencer, DHWatson, Brit. Pat. No. 1036694).

Starting from 2-aminobenzonitrile and Isocyanatoessigsaureethylester of 1,2,3,4-tetrahydro-2,4-dioxo-quinazolin-3-yl-acetic acid ethyl ester (II: n = 0, X = CH ₂₁ R ¹ = C was ₂ H ₆ ) (E.I.Pnpadopoulos, J. Heterocycl.Chem.18, 515 (1981); EPPapadopoulos, CDTorres, J. Heterocycl.Chem.19,269 [1982]).

Some esters of the general formula II were prepared from anthranilic acid esters via the o-isocyanatobenzoic acid esters, their reaction with amino acid esters to give the corresponding o-ureidobenzoic acid esters or derivatives thereof and subsequent cyclization (E. Wolf, H. Kohl, J. Liebig Ann. 1245; N.Yamaya, N.Chau, Y.Iwakura, Seikei Daigaku Kogakubu Kogaku Hokoku 33,2239 [1982], Chem. Abstr. 97,72 322g [1982]; F. Kienzle, A. Kaiser, RE Minder, HeIv Chim. Acta 66,

However, these methods are not generally applicable.

Object of the invention

The aim of the invention is to provide biologically active 1,2,3,4-tetrahydro-2,4-dioxo-quinazolin-3-yl-alkanoic acid esters in practice in the desired variety, in sufficient quantity and using more environmentally friendly and less hazardous agents To make available.

Explanation of the essence of the invention

The object of the invention is to develop a simple, generally applicable process for the preparation of compounds of general formula II, which is characterized by technically easy to handle starting materials.

According to the invention, a 2-alkoxy-3,4-dihydro-4-oxo-quinazolin-3-yl-alkanoic acid ester of the general formula I in solution or in suspension in an organic solvent or without solvent with water to a 1,2,3, 4-tetrahydro-2,4-dioxoquinazolin-3-yl-alkanoic acid ester of the general formula II implemented.

In general formulas I and II, R and R ² (same or different) are alkyl, X is alkylene (straight-chain (C ₁ -C ₁₀ ) or branched, optionally substituted), R ^{1 is} alkyl, alkoxy, halogen, CF ₃ , NO ₂ , CN or N (alkyl) ₂ and η for 0 to 4, wherein in the cases η = 2,3 or 4, the R ^{1 are the} same or different.

Suitable solvents are all water-miscible solvents or mixtures thereof with water. It is advantageous to carry out the reaction in the presence of an acid, with catalytic amounts being sufficient. It is surprising that the 2-alkoxy group is hydrolyzed under these mild conditions and the ester group remains intact. The

Reaction can be carried out at room temperature or with heating, in the latter case the reaction time

is shortened.

The inventive method is generally applicable and is easy to handle and, compared to the

known processes, environmentally friendly and less hazardous starting materials that are commercially available products or can be prepared by known methods. It provides the compounds of general formula II in the desired

Diversity and in sufficient quantities. The compounds of general formula II are biologically active. Among them are those that have a fungicidal or

show plant growth regulatory activity.

The invention will be explained below by embodiments. embodiments example 1

42mg3,4-Dlhydro-2-methoxy-4-oxo-quinazolin-3-yl-es8l-8-methoxy ester (1: η = 0, X = CH ₂₁ R => R ² = CH ₃ ) are dissolved in 5 ml of methanol. Ee is concentrated 1 drop. Hydrochloric acid added and the reaction mixture for 2 hours on the water to 40-50 ⁰ C heated. After distilling off the solvent in vacuo, the residue is separated by preparative layer chromatography (silica gel PF ₁ Merck). R ₁ = 0.4 (benzene / acetone · * 20: 7), m.p .: 203-207 ⁰ C, yield: 33 mg of 1,2,3,4-tetrahydro-2,4-dioxo-3- chlnazolin yl-acetic acid methyl ester (II: η = 0, X = CH ₂ , R ¹ = CH ₃ ).

Example 2

276 mg of (2-ethoxy-3,4-dihydro-4-oxo-quinazolin-3-yl) -acetic acid ethyl ester (I: η = O, X = CH ₂ , R = R ² = C ₂ H ₆ ) are dissolved in 10 ml of ethanol and 5ml of water with 2 drops of conc. Stirred hydrochloric acid with stirring and kept for 1 hour at 60-70 ⁰ C in a water bath. The mixture is evaporated in vacuo and the residue is recrystallized from ethanol. M.p .: 227-23O ⁰ C, yield: 230 mg of 1,2,3,4-tetrahydro-2,4-dioxo-quinazolin-3-yl-6-acetic acid ethyl ester (II: η = 0, X = CH ₂ , R ² = C ₂ H ₆ ).

Example 3

Methyl 2,62g3- (3,4-dihydro-2-methoxy-4-oxo-quinazolin-3-yl) -propanoate (1: n = 0, X = CH ₂ CH ₂ , R = R ² = CH ₃ ) in 20ml dioxane and 5ml water with 2 drops conc. Sulfuric acid and stirred for 2 hours at 40-5O ⁰ C in a water bath. It is evaporated in vacuo and the residue recrystallized from methanol / water. M.p .: 179-181 ⁰ C, yield: 2.12 g? (II) Sat tetrahydro -dloxo-quinazolin-S-yl-propanoic acid methyl ester (II: η = 0, X = CH ₂ CH ₂ , R ² = CH ₃ ).

Example 4

Methyl 2,76g4- (3,4-dihydro-2-methoxy-4-oxo-quinazolin-3-yl) -butanoate (1: η = O, X = CH ₂ CH ₂ CH ₂₁ R = R ² = CH ₃ ) , 30ml of methanol and 5ml of water are concentrated with 2 drops. Hydrochloric acid and heated for 30 minutes under reflux. The mixture is evaporated in vacuo and the residue is recrystallized from methanol / water. M.p .: 156-158 ⁰ C, yield: 2.20 g of 4-0,2,3,4-tetrahydro-2,4-dioxo-quinazolin-3> yl) butanoic acid methylester (ll: η = 0, X = CH ₂ CH ₂ CH ₂₁ R ² = CH ₃ ).

Claims (3)

1. A process for the preparation of I ^ .SATetrahydro ^ -Dioxochlnazolin-S-yl-alkanoic acid esters of the general formula II, characterized in that a 2-alkoxy-3,4-dihydro-4-oxoquinazolin-3-yl-alkanoic acid ester of general formula I in solution or in suspension in an organic solvent or without solvent with water to give a 1,2,3,4-tetrahydro-2,4-dioxo-ch! nazolin-3-yl-alkanoic acid of the general formula II, where in the general formulas I and II R and R ² (identical or different) are alkyl, X is alkylene (straight-chain [C ₁ -C ₁₀ ] or branched, optionally substituted), R ^{1 is} alkyl, alkoxy, halogen, CF ₃ , NO ₂ , CN or N (alkyl) ₂ and η stand for 0 to 4, wherein in the cases η = 2,3 or 4, the R ^{1 are the} same or different. 2. The method according to claim 1, characterized in that one works in the presence of an acid. 3. The method according to claim 1 and 2, characterized in that one carries out the reaction at room temperature or under egg warming.