KR800000383B1 - Preparing process for 3-isoxazoly urea derivatives - Google Patents

Abstract

3-Isoxazolyl urea derivs. (I; R=H, alkyl or aryl, R1=H, alkyl, R2 and R3 are H, alkyl, alkenyl, alkinyl, aralkyl, aryl, alkoxy, alkylthio, X=H, alkyl or halogen) were prepd. by the reaction of 3-isoxazolylamine(II; R, R1 and X are given) with carbaminic acid derivs.(III; A = reaction residue group, R2 and R3 are given). Thus, a mixt. of 3-amino-5-methylisoxazole 490.6 mg and pyridine 3 g, chlorodimethylcarbamoyl 1.18 g was heated at 60≰C for 5.5 hr to give 1.1-dimethyl-3-(5-methyl-3-isoxazolyl) urea 0,4735 g.

Description

Method for preparing 3-isoxazolyl urea derivative

The present invention relates to a process for the preparation of isoxazolyl derivatives of the following general formula (I).

In the above formula

R represents hydrogen, an alkyl group or an aryl group,

R ¹ represents hydrogen or an alkyl group

R ² and R ³ represent hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group, an alkoxy group or an alkalthio group, and R ² and R ³ may be directly connected or indirectly connected by containing a hetero atom. It may form a summon, X may represent hydrogen, an alkyl group or a halogen, R and X may connect and form an alkylene group, and the said alkyl group, an aralkyl group, and an aryl group may be a halogen, an alkyl group, a nitro group. And one or more substituents selected from hydroxy groups.

The isoxazolyl urea derivative other than general formula (I) according to the present invention is reacted with a reactive derivative (III) of 3-isoxazolylamine and carbamic acid of the following general formula (II) as shown in the following reaction formula: It can manufacture.

Where

A represents a reactive moiety (eg halogen, ester residue).

R, R ¹ , R ² , R ³ and X are as described above.

Supplementary terms for the terms defined above include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like. Examples of the vinyl group include vinyl, aryl, propenyl, butenyl, butadienyl, and cyclohexenyl. Examples of the alkynyl group include ethynyl, propenyl and butynyl, and aralkyl groups include benzyl and phenethyl. Examples of the group include phenyl, naphthyl, and the like. Examples of the alkoxy group include methoxy, ethoxy, propoxy and butoxy. Examples of the alkylthio group include buckwheat thio, ethyl thio, propyl thio, and pentyl thio. , Fluorine, bromine, iodine and the like, and examples of the alkylene group include tetramethylene and pentamethylene.

The process of the present invention is the reaction of a reactive derivative of carbamic acid (eg halogenide, ester) with an amine and with or without an inert solvent in the presence of a basic catalyst (eg pyridine, triethylamine). What is necessary is just to carry out under heating.

Examples of the solvent include dimethylformamide, chloroform, detrahydrofuran, benzene and the like, but may also serve as a solvent such as a basic catalyst such as pyridane.

The amine (II) used as raw material in the process of the present invention is derived from the corresponding carboxylic ester (IV) as shown in the following formula.

In the above formula

R ⁴ represents an alkyl group

R and X are as described above.

The 3-isoxazolyl urea derivatives of the general formula (I) thus prepared are novel compounds and are useful as herbicides or algaeicides.

The method of the present invention is described in detail below as examples.

Example 1

To 490.6 mg of 3-amino-5-methylisoxazole, 3 g of pyridine and 1.18 g of dimethylkatbamoyl chloride were added, followed by stirring at 60 ° C. for 5.5 hours. The pyridan is distilled off under reduced pressure, and the residue is added with 1.5 ml of water and 5% hydrochloric acid to pH 1 and extracted with chloroform. Chloroform is distilled off from the chloroform layer, 2.5 ml of 1.5% methanolic sodium hydroxide solution is added to the residue, left at room temperature for 2 days, and the solvent is distilled off. 100 ml of water is added to the residue, acidified with hydrochloric acid, extracted again with chloroform, the chloroform layer is washed with water, dehydrated with sodium sulfate, and the solvent is distilled off. The residue was purified by column chromatography using silica gel to obtain 0.4735 g of 1,1-dimethyl-3- (5-methyl-3-isoxazolyl) urea as a crystal having a melting point of 150.5 to 151.5 占 폚. Yield 56%

Example 2

The reaction was carried out in the same manner as in Example 1 using 3-methylamino-5-t-butylisoxazole, and as crystals having a melting point of 90.0 to 91.0 ° C, 1,1,3-trimethyl-3- (5-t-butyl- 3-isoxazolyl) urea was obtained.

Claims (1)

Preparation of 3-isoxazolyl derivative of the following general formula (I) characterized by reacting 3-isoxazolylamine of the following general formula (II) with a reactive derivative of carbamic acid of the following general formula (III) Way.

Where R represents hydrogen, an alkyl group or an aryl group, R ¹ represents hydrogen or an alkyl group, R ² and R ³ represent hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group, an alkoxy group or an alkylthio group, and R ² and R ³ may be directly connected or indirectly connected by containing a hetero atom. You may form a Summon. X represents hydrogen, an alkyl group, or halogen, R and X may be connected to form an alkylene group, and the alkyl group, aralkyl group and aryl group may have at least a substituent selected from halogen, alkyl group, nitro group and hydroxy group, A represents a reactive moiety.