JPS6144879A - Production of 3-oxo-hexahydro-1,2,4-triazine - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a herbicide by a short production process advantageously without using an expensive raw material such as sodium boron hydride, by using easily obtainable inexpensive N-aminoethylurea as a starting raw material, reacting it under heating. CONSTITUTION:N-Aminoethylurea shown by the formula I is used as a raw material, and reacted under heating to give a compound shown by the formula II. The reaction temperature is 70-200 deg.C, preferably 100-150 deg.C, the reaction may be advanced ina neutral aqueous solution, or a basic aqueous solution, but it is preferably carried out in an acidic aqueous solution containing especially sulfuric acid, hydrochloric acid, etc. The reaction time is 3-15hr when the reaction is done in the aqueous solution of sulfuric acid at 100-150 deg.C. In the example, a solution consisting of 100g compound shown by the formula I, conc. 200g conc. sulfuric acid, and 60g water is reacted at 140 deg.C in an autoclave, the reaction mixture is cooled, neutralized with 20wt% aqueous solution of caustic soda, water is evaporated, the solution is concentrated to dryness, insoluble substances are filtered, and methanol is recovered, to give the titled substance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a process for producing 3-oxo-hexahydro-1,2,4-)riazine, which is useful as a herbicide.

PRIOR ART It is known that the target compound of the present invention can be produced by the following method.

3-oxo-2,3-dihydro- having the formula (wherein A represents a hydrogen atom, a hydroxyl group, an amino group or a group represented by RNH-; KR represents a lower alkyl group or a phenyl group) 1,2,4-triazine derivatives or 3-oxo-2,3,4,5-tetrahydro-
This is a catalytic hydrogenation method using palladium or platinum oxide as a tactile agent for 1,2,4-triazine (Japanese Unexamined Patent Publication No. 115778/1983).

Regarding substitutions and methods for producing compounds having the formula (1), for example, 3-hydroxy-5-mercapto-1,2゜4 having the formula obtained through five steps starting from thiosemicarbazide.
- Method for aminating triazines (J, Am.

Chem, 8oc, 78 1958-41,
(1956)) and thiosemicarbazide.
A process for reacting 3-methylthio-1,2,4-tri-1dine with the formula obtained in steps with sodium borohydride (J.

Heterocyclic Chem, 7 (4)
767-771 (1970).

18(!l) 7551-652 (1981))
etc. are known.

Problems to be Solved by the Invention This method requires a long manufacturing process or requires the use of expensive raw materials such as sodium borohydride, and is not an industrially advantageous method.

As a result of various studies on the rearrangement reaction of N-1 minoethylene urea, the researchers found that by heating it, 3-oxo-hexahydro-1,2,4- ), and completed the present invention.

The reaction temperature is 70°C to 200°C per K in carrying out the present invention.
It can be carried out at a temperature range of 100-100°C, but preferably
The temperature is 150°C. Although the reaction proceeds in a neutral aqueous solution or a basic aqueous solution, the reaction in an acidic aqueous solution containing sulfuric acid, hydrochloric acid, etc. is particularly preferred.

The reaction time varies depending on the reaction temperature and pHK, but if the reaction is carried out in an aqueous sulfuric acid solution at a reaction temperature of 100°C to 150°C,
There are 3 hours to 15 hours η.

Effects of the Present Invention The starting materials for the method of the present invention are easily obtained from inexpensive industrial raw materials, and the target compound can be obtained in high yield.

Example Next, the present invention will be specifically explained with reference to Examples.

Example 1 N-aminoethylene urea 10. Of, 1a sulfate 2αO
f, a solution consisting of 60 f of water at 140°C in an autoclave.
It reacted for 5 hours. After cooling, it was neutralized with a 20% aqueous solution of caustic soda, and the water was evaporated to dryness. After adding 100 m of methanol and filtering the insoluble materials, methanol was recovered from the F solution, 50 m of chloroform was added to the residue, the insoluble materials were collected and dried to give 9.2 tons of 3-oxohexahydro-1. ,2
,4-)su1dine was obtained (yield 92.0%).

Example 2 A solution consisting of 1[LOf of N-aminoethylene urea and 6Of of water was heated under reflux at normal pressure for 30 hours. Water was evaporated to dryness under reduced pressure, post-treated in the same manner as in Example 1, and 3-
Oxohexahydro-1,2,4-triazine was obtained (
yield 82.0%).

Hodogaya Chemical Industry Co., Ltd.

Claims (1)

[Claims] Formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Formula II characterized by subjecting N-aminoethylene urea having I to a thermal reaction ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ 3 having II -Production method of oxo-hexahydro-1,2,4-triazine.