JPS61140573A - Aminobenzoxazine derivative and preparation thereof - Google Patents

Abstract

NEW MATERIAL:The aminobenzoxazine derivative of formula I (R<1> is alkyl, alkenyl, alkynyl, alkoxyalkyl or alkoxyalkoxyalkyl; R<2> is H or CH3). EXAMPLE:6-Amino-7-fluoro-4-propargyl-2H-1,4-benzoxazin-3(4H)-one. USE:Intermediate of herbicide. PREPARATION:The compound of formula I can be produced by reducing the compound of formula II with iron powder. The obtained compound of formula I can be converted to the compound of formula III useful as a herbicide by reacting with 3,4,5,6-tetrahydrophthalic anhydride. The starting compound of formula II can be produced by reducing and cyclizing the compound of formula IV (R<3> is lower alkyl) with iron powder, selectively nitrating the resultant compound of formula V with a mixture of sulfuric acid and nitric acid, and reacting the obtained compound of formula VI with the compound of formula R<1>-X (X is halogen).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula [wherein R1 represents an alkyl group, an alkenyl group, an alkynyl group, an alkoxyalkyl group, or an alkoxyalkoxyalkyl group, and R2 represents a hydrogen atom or a methyl group. ] Aminobenzoxazine derivative (
Hereinafter, it will be referred to as the compound of the present invention. ) and its manufacturing method.

A tetrahydrophthal derivative represented by the general formula [wherein R1 and R2 have the same meanings as above], which can be produced by reacting the compound of the present invention with 8,4.5.6-titrahydrophthalic anhydride. does not cause harmful chemical damage to major crops such as corn, wheat, rice, dice, and cotton, and has sufficient herbicidal efficacy against many weeds (Japanese Patent Application No. 198245-1981))
The compound of the present invention typically has the general formula [where ul and R2 have the same meanings as above]. ] of the 4-substituted ditropenzoxazine derivative represented by 3 to 30 equivalents, preferably 5 to 20 equivalents of iron powder, in acetic acid water, preferably in the presence of a co-solvent such as ethyl acetate. , by reduction at 60°C to 120°C.

After the reaction is completed, the reaction solution is separated from the residue, extracted with an organic solvent, and the extracted solution is washed with water, sodium bicarbonate, etc., and then subjected to post-treatment such as concentration, or if necessary, recycled. The desired compound of the present invention can be obtained by purification by operations such as crystallization and chromatography.

Note that the 4-substituted nitrobenzoxazine derivative, which is a raw material compound, can be produced by the following method. That is, in the general formula C, R3 represents a lower alkyl group, and R2 has the same meaning as above. ] phenoxyacetic acid ester/L/i, ? -1”L
3 to 30 equivalents, preferably 5 to 20 equivalents. "An equivalent amount of iron powder is subjected to cycloreduction in aqueous acetic acid, preferably in the presence of an auxiliary solvent such as ethyl acetate, at 60°C to 120°C to form a compound of the general formula [wherein R2 is The benzoxazine derivative represented by
C. to selectively nitrate the 6-position of the benzoxazine ring, resulting in a compound of the general formula [wherein B2 represents the same meaning as above]. ] was obtained, and then the nitrobenzoxazine derivative [VI] and the general formula % [[wherein R1 represents the same meaning as above and X represents a halogen atom]] in a solvent in the presence of a base,
The 4-substituted ditropenzoxazine derivative [
1[] can be produced.

The compound [■] is 1.0 to 1.5 equivalents, and the base is 1.0 to 1.5 equivalents. o~1
．． 5 equivalents.

Examples of the solvent include aromatic hydrocarbons such as toluene and benzene, amides such as N,N-dimethylformamide, sulfur compounds such as dimethylsulfoxide, nitriles such as acetonitrile, water, etc., or mixtures thereof.

Examples of the base include sodium hydride, potassium carbonate, sodium hydroxide, potassium hydroxide, and the like.

In addition, this raw material compound fenoquine acetate)v
(IVI is J, Am, Chem, Soc,
8194 (1959).

Hereinafter, the present invention will be explained in more detail with reference to production examples and reference examples.

Production example Iron powder 1.05F was suspended in 2.0 ml of 5-thiacetic acid water,
Heated to 80°C. To this was added a solution of 0.47 F of 7-fluoro-6-nitro-4-propargyl 1v-2H-1,4-benzoxazin-8(4H)-one dissolved in 1.9 mA of acetic acid and 1.9 mj of ethyl acetate. In addition, 60℃
The mixture was heated to reflux at ~80°C for 3 hours. After cooling, water and ethyl acetate were added, the residue was separated, and the p liquid was extracted with ethyl acetate. The extract was washed with water and then with aqueous sodium bicarbonate, dried, and concentrated to obtain 6-amitufufluoro-4-propagyl-2.
H-1,4-benzoxazin-8(4H)-one 0
1312 was obtained. Om, p, 188-185°C. Some of the compounds of the present invention that can be produced by such a production method are shown in Table 1. Table 1. General formula: 86.42 t of iron powder was mixed with 69 ml of 5-thiacetic acid water. suspended in
A solution of ethyl 5-fluoro-2-nitrophenoxaacetate/1'15.86y dissolved in 65 mJ of acetic acid and 65 ml/C of ethyl acetate was added to the solution heated to 80°C.
After heating and refluxing at C to 80°C for 3 hours, the 0 residue was taken from house to house, and the p liquid was extracted with ethyl acetate. The 0 extract was washed with water and then with aqueous sodium bicarbonate, dried, and concentrated to give pale yellow crystalline 7-77. Rheolow 2H-1,4-benzoxazin-8(4H)-one 6
．． Similarly, ethyl 2-methy)v-5-fluoro-2-nitrophenoxyacetate, 7-fluoro-2-methyl lv
-2H-1,4-benzoxazin-8(4H)-one was obtained o m, p, 151.11°C Reference example 2 7-fluoro-2H-1,4-penzoxazine-: 1
I(4H)-one2. Of was dissolved in 80 ml of sulfuric acid water. This was cooled to θ°C to 5°C, and 60 nitric acid 1.6
t was gradually added dropwise at 0°C to 5°C, and the mixture was stirred at the same temperature for 30 minutes. This reaction mixture was poured into ice water, and the resulting crystals were
After washing with water and air drying, 7-fluoro-6-nitro-2H-1,4-benzoxazine-
8(4H)-one obtained 2.12 o m, pa 20
5.9°C in the same manner as 7-fluoro-2-methy)V-2
H-1,4-benzoxazin-3(4H)-one, 7-fluoro-2-methyl-6-nitro-2H-1,
4-benzoxazin-8C4H)-one was obtained a
m, p-288, 6°C Reference Example 8 0.06f of sodium hydride was suspended in 8mJ of N,N-dimethylformamide and cooled to 0°C.

To this, 7-71V oro-6-:-)0-2H-1,4
-Benzoxazin-8(4H)-one 0.571 O
Add at ~5°C and press for 30 minutes. Next, 10.354 µg/L of propane bromide was added to this reaction solution, the temperature was gradually raised to room temperature, and the mixture was allowed to react for 6 hours. Water was added, extracted with ethyl acetate, the extract was washed with water, dried and concentrated, and the resulting residue was purified by silica gel column chromatography (developing solvent: ethyl acetate = 5-hexane = 1:1). ,
7-7/L'Olor 6-nitro-4-7-lopargyl-
2H-1.4-penzoxazine-:3 (4H)-one 0.47f was obtained ◇ m, p, 109.1°C 4-substituted nitrobenzoxazine derivative [11r) which can be produced in the same manner. Some are shown in Table 2.

Claims (2)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R^1 represents an alkyl group, alkenyl group, alkynyl group, alkoxyalkyl group, or alkoxyalkoxyalkyl group, and R^2 is a hydrogen atom or Represents a methyl group. ] An aminobenzoxazine derivative represented by. (2) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R^1 represents an alkyl group, alkenyl group, alkynyl group, alkoxyalkyl group, or alkoxyalkoxyalkyl group, and R^2 is a hydrogen atom or Represents a methyl group. ] A general formula characterized by reducing a 4-substituted nitrobenzoxazine derivative with iron powder ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R^1 and R^2 have the same meaning as above. represents. ]
A method for producing an aminobenzoxazine derivative represented by