DD211111A1 - PROCESS FOR PREPARING SUBSTITUTED 6-IMINO-2,4-DIOXO-PERHYDRO-1,3,5-TRIAZINES - Google Patents

Abstract

The Titelverbindgn. are certain derivatives d. 2,4-dioxoperhydro-1,3,5-triazine m. potential biological activity u. Suitability as intermediates f. Syntheses. Target u. Task d. Erfindg. is d. Entwicklg. a new method for Herstellg. this connection The object is achieved by subjecting S-alkyl-2-isothiotriurete in organic optionally water-miscible solvents at temperatures between -10 degrees C and the boiling point of the solvent in the presence of a base of a cyclocondensation reaction, the title compounds in good purity as crystalline substances accumulate.

Description

A method for preparing substituted 6-imino-2 _t ~ 4 ~ j dioxo perhydro * i _t 3T5-triazines

Field of application of the invention:

The invention relates to a process for the preparation of novel derivatives of perhydro-s-triazine-dione with potential biological activity and as intermediates for syntheses ¹ !

Characteristic of the known technical solutions!

Several processes have already been described for the preparation of tetrahydro-1,3,5-triazine-2,4-diones which contain a singly or doubly substituted amino group in the 6-position (DE-OS 2,451,899, No. 2,528,162 , 2603 180). These are based on two or more carbonic acid derivatives such as phosgene, chloroformates, isocyanates, IainodicarbonsäureCester) - chlorides, ureas, isothioureas, carbodiimides, cyanamides and guanidines, which are cyclocondensed together in a suitable combination with each other · The 6-amino group is optionally in a subsequent step introduced nucleophilic substitution of a halogen atom or an alkylthio group; The cyclocondensation is carried out either directly from the starting materials or via stable acyclic intermediates of the biuret or allophanimidate <Pyp (DD-AP IO6 939t 112 65I) ^

The methods already described are considered to be deficient in that they sometimes emanate from hard-to-reach, poorly handled, aggressive or toxic substances that tend to form unwanted by-products. 6-imino-perhydro-1,3j-5 ~ an isocyanate are perhydro-triazine-2,4-diones so far only by the reaction of relatively unstable intermediates carbodiimide with two moles of produced (Chem. Ber, 110/1979 /. 820 ).

The suitability of 6-amino-1,2,3,4-tetrahydro-1,3,5-triazine-2,4-diones as herbicidal, fungicidal and bactericidal agents and as plant growth regulators has already been described (GB-PS 1464248, 1504304; ÜS-PS 3898073? DE-OS 2638519).

Object of the invention:

The aim of the invention is the development of a new rational and technically-economically advantageous process for the preparation of polysubstituted 6-imino-2- _t 4-dioxo-perbydro-1,3,5-triazines having potential biological activity and as intermediates for syntheses.

Explanation of the essence of the invention!

Technical task

The invention has for its object to find a Herstellungsverfsh rim for the title compounds, which emanates from easily accessible, relatively stable intermediates, which can be implemented in a simple manner with good yield to the desired end products: «

Features of the invention:

It has been found that substituted 6-imino-2,4-dioxo-perhydro-1 », 3,5-triazines of general formula I (see Table 1), in which

1 R is an optionally mono- or polysubstituted aryl radical, R is a lower alkyl radical, Ic is a hydrogen atom or

4 is a lower alkyl radical and R is a hydrogen atom, an alkyl radical or an optionally substituted aryl radical,

or the tautomers possible in the case of R equal to hydrogen

12 4 of the general formula Ia (see Table 1) in which R, IT and R have the abovementioned meaning, can advantageously be prepared by reacting an S-alkyl-2-isothiotriuret (1-allophananoyl-isothiourea) of general formula II (s.

14

Table 1), in which the substituents R to R have the same meaning as above and R is a lower alkyl radical, in the presence of a base of a cyclocondensation reaction according to Equation 1 (see Table 1) with elimination of a mercaptan.

The 2-isothiotriurets of the general formula II required as starting materials for the process according to the invention can be prepared relatively easily from S-alkylisothioureas and 1-chlorocarbonylureas (allophanyl chlorides) (DD-VP application "). By the extent possible free

1 4

Choice of Substituents R to R, the method offers the possibility of synthesizing many new members of the class of title compounds with particular substitution patterns ·

For the cyclocondensation reaction, the 2-isothiotriuretes are expediently dissolved or suspended in a water-miscible aprotic-dipolar organic medium. The reaction will be initiated by the addition of an inorganic or organic base such as alkali metal hydroxides or carbonates or basic amines and will generally proceed spontaneously at room temperature with sufficiently high rate to eliminate the mercaptan. The use of an equivalent amount of alkali is desirable for binding the mercaptan ·

In the case of compounds of general formula I in which

3 4

Tr and R symbolize hydrocarbon radicals rather than hydrogen atoms, the cyclocondensation proceeds so spontaneously that the intermediate of general formula II prepared from allophanoyl chloride and isothiourea does not have to be isolated and the desired product I is obtained directly. The process according to the invention is illustrated by the following examples ·

EXAMPLES example 1

1- (3,4-dichlorophenyl) -3-methyl-2,4-dioxo-6-isothipino-perhydro-1- _t 3 _> 5 ¹ "· triazine

6.7 g (20 mmol) of S, 5-dimethyl-7- (3 »4-dichlorophenyl) -2-isothiotriuret are suspended in 20 ml of tetrahydrofuran and with stirring a solution of 1 g (25 mmol) of sodium hydroxide in 5 ml of water added dropwise · stirring is continued for 2 hours at room temperature · The reaction mixture is diluted with 100 ml of water, the resulting precipitate is filtered off with suction, washed with water and dried · This gives 5 g (82.2 % d · Th,) of the title compound, mp 331 -333 ⁰ C

Example 2

1-phenyl-3 "5""-dimethyl-2- _t 4-dioxo-6-phenylimino-perhydro-1,3- _t- 5-triazine

18.5 S (60 mmol) of N, 2-dimethyl-N-phenylisothiuroniua-iodide are dissolved in water and neutralized with 6.4 g (60 mmol) of sodium carbonate. The solution is extracted three times with 50 ml of ether each time dried ether extract is mixed with 5t1 S (50 mmol) of triethylamine. With stirring, a solution of 10.6 g (50 mmol) of 2-methyl-4-phenyl-allophanoyl chloride in 40 ml of ether is added dropwise and the mixture is boiled for 2 hours. After cooling, it is filtered and the filtrate is evaporated. Treating the residue with ethanol / ether yields a colorless crystal which, after purification, provides 4.4 g (28.5 % of theory ) of the title compound; F. 1? 5-1? 7 ⁰ C

- 6 table 1

ο. > ³

r ² -n'Vn-r ⁴

K.

SR

•

ET II

Xi ------ - RSH J. VDZW. ί BiJ ^C 6 ^H 5 R ² R ³ _R 4 υπ · ι Table 2 3-CH ₃ C ₆ H ₄ CH ₃ H e Verb Vf, Substituents HR ¹ 4-ClC ₆ H ₄ CH ₃ H H P. ( ⁰ C) 1 CHj 3,4-Cl ₂ C ₆ H ₃ CH ₃ H H 332-334 2 CHj ^C 6 ^H 5 CH ₃ H H 306-307 3 CHj CH ₃ CH ₃ ^C 6 ^H 5 ^C 6 ^H 5 326-329 * CHj 331-333 5 6 CHj 175-177 163-165

Claims (1)

invention claim Process for the preparation of substituted 6-imino-2,4-dioxo 1 perhydro-1,3 »5" * trisL2iinen de? General formula I, in the pure optionally mono- or polysubstituted aryl radical, 2 3 R is a lower alkyl radical, Ir is a hydrogen atom or a lower alkyl radical and R is a hydrogen atom, an alkyl radical or an optionally mono- or polysubstituted aryl radical, or their tautomers, of the general formula Ia, in which R, R and R have the abovementioned meaning, characterized in that an alkyl-2-iso- 1 thiotriuret of the general formula II in which the radicals R to R have the same meaning as above, and which is optionally prepared fresh from an allophanoyl chloride and an S-alkyl-isothiourea and used without separation and purification, in a water-miscible or immiscible dipolar-aprotonic organic solvent at temperatures between -10 ⁰ C. and the boiling point of the solvent in the presence of a base for cyclocondensation to release a mercaptan ·