CA1264323A - Amino or nitro derivatives of benzoxazole-2-one and benzoxazin-3-one - Google Patents

Abstract

Abstract:
The invention provides compounds of the formula:
wherein R1 is a hydrogen atom, a C1-C5 alkyl group, a C3-C4 alkenyl group, a C3-C4 alkynyl group, a C1-C4 haloalkyl group, a C3-C4 haloalkenyl group, a C3-C4 haloalkynyl group, a C1-C2 alkoxy (C1-C2) alkyl group or a C1-C2 alkoxy-(C1-C2) alkoxy(C1-C2)alkyl group, R2 and R3, which may be the same or different, each represents a hydrogen atom, a halogen atom, a C1-C3 alkyl group or a phenyl group, X
is a hydrogen atom, a chlorine atom or a fluorine atom, n is an integer of 0 or 1 and A is an amino group on a nitro group. These compounds are useful as starting compounds in the preparation of tetrahydrophthalimides. The tetrahydrophthalimides are useful as herbicides.

Description

12~;4~

Amino or Nitro Derivatives of Benzoxazol-2-One and Benzoxazin-3-One The present application has been divided out of Canadian Patent Application Serial No. 487,286 filed July 23, 1985.
This invention relates to amino or nitro compounds useful as starting compounds in the preparation of tetrahydrophthalimides.
It is known that certain kinds of tetrahydro-phthalimides are useful as herbicides. For instance, the herbicidal use of 2-(4-methoxyphenyl)-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione is disclosed in U.S. patent 3,878,224. However, the herbicidal effect of these compounds is not always satisfactory.
According to the invention there is provided a compound of the formula (I):

4~

~ X

O N A
(I) wherein Rl is a hydrogen atom, a Cl-C5 alkyl group, a C3-C4 alkenyl group, a C3-C4 alkynyl group, a Cl-C4 haloalkyl group, a C3-C4 haloalkenyl group, a C3-C4 haloalkynyl group, a Cl-C2 alkoxy(Cl-C2)alkyl group or a Cl-C2 alkoxy(Cl-C2)alkoxy(Cl-C2)alkyl group, R2 and R3, which may be the same or different, each represents a hydrogen atom, a halogen atom, a Ci-C3 alkyl group or a phenyl group, X is a hydrogen atom, a chlorine atom or a fluorine atom, n is an integer of 0 or l and A is an amino group or a nitro group.
The term "halogen~ used herein includes chlorine, bromine and fluorine.
An amino compound of the formula (I) (i.e. a compound wherein A is an amino group) can be reacted with a 3,4,5,6-tetrahydrophthalic anhydride in a solvent at a temperature of 80 to 200C for a period of l to 24 hours to obtain a compound of the formula:
o~N/~ ~J (II) R
o wherein R2, R3, X and n are as defined above. In the reaction, the 3,4,5,6-tetrahydrophthalic anhydride is used in an amount of l to 3 equivalents to l equivalent of the amino compound (I). Examples of the solvent are aliphatic hydrocarbons (e.g. hexane, heptane, ligroin), aromatic hydrocarbons (e.g. benzene, toluene, xylene), ethers (e.g.
diisopropyl ether, dioxane, ethylene glycol dimethyl ether), fatty acids (e.g. formic acid, acetic acid, propionic acid), water, and mixtures thereof.
After completion of the reaction, the reaction mixture is subjected to ordinary post-treatment. For instance, the reaction mixture is, if necessary, admixed with water, and the precipitated crystals are collected by filtration.
Alternatively, the reaction mixture is optionally admixed with water, followed by solvent extraction or concentration.
Further, if necessary, the purification by chromatography or recrystallization may be applied.
It has been found that the tetrahydrophthalimides of formula (II) show a high. herbicidal activity against a wide variety of weeds including broad-leaved weeds, Graminaceous weeds, Commelinaceous weeds and Cyperaceous weeds in agricultural plowed field by foliar or soil treatment without producing any material phytotoxicity on various agricultural crops such as wheat, barley, corn, soybean and peanut. Examples of broad-leaved weeds are wild buckwheat (Polygonum convolvulus) ladysthumb (Polygonum persicaria), pale smartweed (Polygonum lapathifolium), common purslane (Portulaca oleracea), common i4;~

chickweed (Stellaria media), common lambsquarters (Chenopodium album), redroot pigweed (Amaranthus retroflexus), radish (Raphanus sativus), wild mustard (Sinapis arvensis), hemp sesbania (Sesbania exaltata), sicklepod (Cassia obtusifolia), velvetleaf (Abutilon theophrasti), prickly sida (Sida spinosa), field pansy (Viola arvensis), catchweed bedstraw (Galium aparine), ivyleaf morningglory (Ipomoea hederacea), tall morningglory (Ipomoea purpurea), henbit (Lamium amplexicaure), jimsonweed (Datura stramonium), black nightshade (Solanum ~ ), persian speedwell (Veronica persica), common cocklebur (S~nthium pensylvanicum), common sunflower (Helianthus annuus), scentless chamomile (Matricaria perforate), pineappleweed (Matricaria matricarioides), oxeye daisy (Chrysanthemum leucanthemum), corn marigold (Chrysanthemum segetum), sun spurge (Euphorbia helioscopia), etc. Examples of Graminaceous weeds are Japanese millet (Echinochloa frumentacea), barnyard-grass (Echinochloa crus-galli), sicklepod (Cassia obtusifolia), large crabgrass (Digitaria sanguinalis), annual bluegrass (Poa annua), blackgrass (Alopecurus myosuroides), oats (Avena sativa), wild oats (Avena fatua), johnsongrass (Sorghum halepense), etc. Examples of Commelinaceous weeds are asiatic dayflower (Commelina communis), etc. Examples of Cyperaceous weeds are yellow nutsedge (Cyperus esculentus), etc.
Upon the pre-emergence soil treatment, the tetrahy-drophthalimides (II) exhibit a particularly strong herbicidal activity against broad-leaved weeds such as catchweed bedstraw, common chickweed, field pansy, persian speedwell, scentless 4~

chamomile, pale smartweed, ladysthumb, wild mustard, pineapple-weed, oxeye daisy, common lambsquarters, black nightshade, field bindweed and redroot pigweed in the field of wheat or barley while exerting no or little chemical injury to wheat or barley; they also exhibit a marked herbicidal activity against broad-leaved weeds such as velvetleaf, common cocklebur, tall morningglory, sicklepod, prickly sida, jimson weed, hemp sesbania, redroot pigweed, common lambsquarters and black nightshade in the field of soybean or peanut while exerting no or little chemical injury to soybean or peanut.
Further, some of the tetrahydrophthalimides (II) of the invention are effective in exterminating paddy field weeds including Graminaceous weeds such as barnyardgrass (Echinochloa oryzicola), and broad-leaved weed such as commonfalsepimpernel (Lindernia procumbens), indian toothcup (Rotala indica), and wate~wort (Elatine triandra), without any phytotoxicity to rice plants on flooding treatment.
Among the compounds of the formula (I), those wherein X is a hydrogen atom or a fluorine atom are preferred. More preferred are those wherein Rl is a Cl-C4 alkyl group, a C3-C4 alkenyl group, a C3-C4 alkynyl group, a C3-C4 haloalkynyl group or a Cl-C2 alkoxymethyl group and R2 and R3 are each a hydrogen atom, a methyl group or an ethyl group. Much more preferred are those wherein Rl is a Cl-C3 alkyl group, a C3-C4 alkenyl group, a C3-C4 alkynyl group or a halopropynyl group, especially n is an ~;43~:~
- 5a ~

integer of 1. Most preferred are those wherein R2 is a hydrogen atom or a methyl group and R3 is a hydrogen atom, especially when R1 is a C3-C4 alkenyl group or a C3-C4 alkynyl group.
Specific preferred tetrahydrophthalimides of the formula (II) are 2-[4-(2-propynyl)-2H-1,4-benzoxazin-3(4H)-on-6-yl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione, 2-[2-methyl-4-(2-propynyl)-2H-1,4-benzoxazin-3(4H)-on-6-yl3-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione, 2-[7~fluoro-4-(2-propynyl)-2H-1,4-benzoxazin-314H)-on-6-yl3-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione, 2-[7-fluoro-2-methyl-4-(2-propynyl)-2H-1,4-benzoxazin-3 (4H)-on-6-yl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione, etc.
Practical and presently preferred embodiments for production of the compounds of the formula (I) of the present invention as well as the tetrahydrophthalimides of the formula (II) described in the parent application, Canadian Patent Application Serial No. 487,286 are illustratively shown in the following Examples.

1~;4~

Example l A mixture of 6-amino-4-~2-propynyl~-2H-1,4-benz-oxazin-3(4H)-one (0.8 g), 3,4,5,6-tetrahydrophthalic an-hydride (0.61 g) and acetic acid (20 ml) was heated under reflux for 2 hours. After being allowed to cool, water was added to the mixture, and the precipitated crystals were collected by filtration and washed with water. Recrystal-lization from ethanol gave 2-[4-(2-propynyl)-2H-1,4-benz-oxazin-3(4H)-on-6-yl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione (0.4 g). m.p., 205 - 2~6C.
lH-NHR (CDC13) ~ ppm: 1.8 (4H, m), 2.2 (lH, t),

2.4 (4H, m), 4.6 (2H, s), 4.62 (2~, d), 7.0 - 7.3 (3H, m).
Example 2 A mixture of 6-amino-7-fluoro--4-(2-propynyl)-2~-1,4-benzoxazin-3(4H)-one (0.31 g), 3,4,5,6-tetrahydro-phthalic anhydride (0.28 g) and acetic acid (3 ml) was heated under reflux for 2 hours. After being allowed to cool, water was added to the mixture, which was then extracted with ethyl acetate. The organic layer was washed with water, neutralized with sodium bicarbonate solution, dried and concentrated. The residue was purified by silica gel thin layer chromatography using a mixture of ethyl acetate and hexane (l : 2) as an eluent to give 2-[7-fluoro-4-(2-propynyl)-2H-1,4-benzoxazin-3(4H)-on-6-yl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione (0.12 g). m.p., 196.0C.
H-NHR (CDC13) ~ ppm: 1.81 (4H, m), 2.4 (4H, m), 2.53 (lH, t), 4.52 ~2H, s), 4.73 (2H, d), 6.88 (lH, d, J =

4;3~;~

10 Hz), 7.04 ~1~, d, J = 6 Hz).
Exam~le 3 A mixture of 5-amino-3-(2-propynyl)-3H-benz-oxazol-2-one (0.50 g), 3,4,5,6-tetrahydrophthalic anhydride (0.53 g) and acetic acid (5 ml) was heated at 100 to 110C
under reflux for 3 hours. After being allowed to cool, water was added to the mixture, which was then extrac.ed with ethyl acetate. The organic layer was washed witA
water, neuralized with sodium bicarbonate solution, dried and concentrated to give 2-[3-(2-propynyl)-3H-benzoxazol-2-on-5-yl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione (0.30 g). m.p., 285.5C.
lH-NHR (CDC13) ~ ppm: 1.8 t4H, m), 2.22 (1~, t), 2.4 (4H, m), 4.60 (2H, d), 7.0 - 7.3 (3H, m).
In the same manner as above, the tetrahydrophthal-imides ~s shown in Table 1 were obtained.

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_ ~- O o ~ O ~ Ul ~ ~J N 1-- O

_ ~3 O W N
ooooo :~ ~\ (D

~ ~ O ~ O
N111 1ll ~__ g o //

3 1 ~ W N 3I ~ NW ~ N N d ~ W ~ CI I I_ ~=~
~ I N ~ \
~ X
0~ ~0 ~ N

X ~ 3 ~ X

3 3 3 ~ 3 3 3 3 3 3 3 ~o ~a ~ ~ ~ ~ ~ ~
~.......................... , ~J
1~ N N 1~ N
N ~ NW ~ V-W ~ ~0 CO P~
O O 1-- N ~ ~Jl I_ I I . I. I II ~ I .
1~ Jl 1~ 0 N1~~ ~ ~
~ N I NO ~ 111 W ~ ~D o O
~ W ~ NW0~ (~
o .~JI o o oo o o tl~
O~ DJ
t~ ~) _ 1~i4;~
g , _ . o o ~ ~ W ~ ,3 ~::

,~ y ,_,_ O ~ O ~ 1' W ~ Vl I ~0 1 ~
P~

I~n Vl W W

W

~ X

3 3 3 3 3 ~ 3 3 3 3 3 ~ 3 3 ~ ~3 .............. ,'_ . :J
o . . . . . . . . . . . tn ~ ~n 3' 1~ 'C ~ ~ C
a~ ~I ~ ~ w ~ oa~ ~n O~
1-- ~ w ~ wa~ ~~D O ~ 1-- ~
I . . . I . I . I I I . I I I _ 1~ D ~ Ot~ ~
~ I I O~J O_l O ~ ~~n I o a~ ~n O
w 1~ ) w o1~ 3 O ~ o o o ~ oa~ o ~ o ~1 1-~ ~11 W
. . o o o P~
~nO ~nO ~
~ _ 1~4;~
~ 10 -W W W W W W W W ~ ~ ~ o o co ~ (n ~ w ~ 1- 0 ~O ~ 3 O

~ _ ~ 3 :: \ / \ / \ ~ \ / 111 111111 111 111 lli o ~ n / \ / ~ / ~ ~ \ ~ ~ ~ lV lV
O ~ n 5 n, , I I I I ,_ l-- ~ i~ i-- $ i-- 5:
l l l l l 3 W~
~ ~ ~ W W
l l l ~ ~d :~ :I $ ~ ~

:1: ki k.i ~ X ~ X
_ ~i _i 3 ~-i -i 3 3 3 ~ 3 3 O
W w . . . . .. .. ~.~ ~' _ ~ CO 1-- ~ C
~ w a~ ~ co WD) ID
W ~ -- Ul ~S~ 1-- .~O I_ ~
I . I I I . ul ~ (n Ul. _ ~n 1-- 1-- 1-- ~ ~ ~ a~ I ul~
I a~ o ~ I~ ~D ~DI O
~ O ~ O t-- o )-- :1 W o o o . ,PU~
o~ O o ~--o . o .~) (~ n3`

~~ ~
_ l~li4;~

_ Ul ~ ~ ~ ~ ~ ~ ~ ~P ~ ~ W o g o ~ n ~ W ~ ~ o ~D ' 3 o ,~

/ ~ P
~-I~

~ N
l l C
~y ~ X ~ C ~

~ X
3 3 . 3 3 3 3 3 C1~ 33~ ~ ~ o' n~ l~ ,t . . . . . . . . . . . . Ul ( n o 1.. ~5 l~ ~ ~:
_l ~ ~ O~D ~n )~ n P~ ~D
~I O ~ ~ > O ~ W ~_ C)~
I . . . I . I ~n I ~n I _ ~,n ~ n ~-- ~n ~ n ~-- Q
I ~ o I IUl ICo ~ n O
1~ 0 0 ~ G ~ ::1 ~I o o ~ o ~) o o o tn ~ ~t ;n ~;n ~
o o ~t _

4~

The production of the amino compound is summarized in the following scheme:

$;~
- 13 ~

t R2~C)~X

o I N~2 al f a /;t R~
reduc- \ Rl~ tV) R2 ~ ~ 2~X

O N N02 aN ~2 R' (IV) ~ ~ (XY) reduc-1 Rl~ (V) tlon ( ~C)n ~ 0~ ~~X

O~N N02 R4 2~ N02 (III) , ~ (ILIV) n-O jl~ n-l ~\ ~\ R4Z
(x-~ a) Q-C-C02R5 \ \ R2~ ~
Rz ~3 ( X'-F,Cl) ~ (X'-F,Cl) ~ ~OJ~O 02NJ~NOz UZU~I1O~-<;~ 1'o~3' 1 1 (Yl) (VIII) (X) 3~ ~ X

~0~ R2~ ~X' ~ (XII) N R~,O 2 ~
(Vll) (IX) ~ (XI) 43;~;~

wherein Rl, R2, R3, X and n are each as defined above, x' is a fluorine atom or a chlorine atom, Y is a halogen atom, % is a hydroxyl group, Q is a halogen atom, Rl is a Cl-C5 alkyl group, a C3-C4 alkenyl group, a C3-C4 alkynyl ~roup, S a Cl-C4 haloalkyl group, a C3-C4 haloalkenyl group, a C3-C4 haloalkynyl group, a Cl-C2 alkoxy(Cl-C2)alkyl group or a Cl-C2 alkoxy(Cl-C2)alkoxy(Cl-C2)alkyl group and R4 and R5 are each a lower alkyl group.
The above conversions will be explained further in detail below.
(1) Production of the compound (IV) from the compound (III) The compound (IV) is obtainable by reacting the compound (III) with the compound (V) in a solvent in the presence of a dehydrohalogenating agent at a temperature of 0 to 80C, preferably of 10 to 30C. The amounts of the compound (V) and the dehydrohalogenating agent are respec-tively 1.0 to 1.5 and 1.0 to 1.5 equivalents to one equiva-lent of the compound (III). Examples of the solvent are aromatic hydrocarbons (e.g. toluene, benzene), amides (e.g.
N,N-dimethylformamide), sulfur compounds (e.g. dimethylsul-foxide), nitriles (e.g. acetonitrile), water, and their mixtures. Examples of the dehydrohalogenating agent are sodium hydride, sodium hydroxide, potassium hydroxide r etc.
After completion of the reaction, the reaction mixture is subjected to ordinary post-tceatment such as the addition o~ water, extraction with an ocganic solvent and 1~i43~;~

( concentration. If desired, any conventional purification procedure such as recrystalli2ation or chromatography ma~ be adopted.
(2) Production of the compound from the compound (IV) The compound is obtained by reducing the compound tIV) with 2.0 to 10 equivalents of iron in the presence of an acid in a solvent (e.g. acetic acid, water, alcohol, tetrahydrofuran) at a temperature of 20 to 100C.
After completion of the reaction, the residue is collected by filtration and extracted with an organic solvent. The extract is washed with water and sodium bicarbonate solution and concentrated. If necessary, the reaction mixture may be purified by recrystallization or chromatography as conventionally employed.
(3) Production of the compound (III) i) Production of the compound (III) (n = 0; X =
H) from the compound (VI):-The compound (III) (n = 0; X = H) can be producedfrom the compound (VI), i.e. 2-amino-4-nitrophenol, by the method as described in J.Am.Chem.Soc., 71, 1265 (1949) and J.Pharm.Sci., 53, 538 (1964).
ii) Production of the compound (III) (n = l; X =
~) from the compound (VI):-The compound (III) (n = 1; X = H) can be producedrom the compound (VI), i.e. 2-amino-4-nitrophenol, by the method as described in Synthesis, 1982, 986.
iii) Production of the compound (III) (n = 0, X =

4~

( F or Cl) from the compound (VII) through the compound (VIII):-The compound (VIII) is obtainable from the compound (VII) by the methoc as described in J.Pharm.Sci., 53, 538 (1964), and the resultant compound (VII) is nitrated by l.0 to l.2 equivalents of 60 % nitric acid in 80 ~
aqeuous sulfuric acid solution at a temperature of -5 to 5C
to give the compound (III).
iv) Production of the compound (III) (n = l, X =
F or Cl) from the compound (~X1 through the compound (X):-The compound (X) is obtained by reducing thecompound (IX), which is produced by the method as described in J.Am.Chem.Soc., 81, 94 (1959), with 2.0 to lO equivalents of iron in the presence of an acid in a solvent (e.g. acetic acid, water, alcohol, tetrahydrofuran) at a temperature of 20 to 100C.
After completion or the reaction, the residue is collected by filtration and extracted with an organic solvent. The extract is was~.ed with water and sodium bicarbonate solution and concentrated. If necessary, the reaction mixture may be purified by recrystallization or chromatography as conventionally employed.
The compound (X) thus obtained is subjected to nitration with a mixture of s~lfuric acid and nitric acid at a temperature of -lO to lOC so as to selectively nitrate the 6-position of the benzoxazine ring to give ~he compound (III) (n = l; X = F or Cl). Sulfuric acid and nitric acid are respectively used in amounts of one equivalent to large ~i4~

( excess and of 1 to 1O2 equivalents to the compound (X). The concentrations of sulf~ric acid ana of ni~ric acid are preferred to be 80 % and 60 %, respectiveiy.
After completion of the reaction, the reaction mixture is poured into ice water, and the precipitated crystals are collected by filtration and washed with water.
If necessary, any purification method such as recrystal-lization or chromatography may be adopted.
(4) Production or the compound (XII) from the compound (XI) The compound (XII) is obtainable from the compound lXI) by the method as described in Rec.Trav.Chim., 76, 128 (1957) and J.Am.Chem.Soc., 65, 1555 (1943).
; (5) Production of the compound (XIV) from the compound (XII) through the compound (XIII) The compound (XIV) is obtainable from the compound (XII) through the compound (XIII) by the method as described in Gazz.Chim.Italiana, 22, I, 242 (1892) and J.Am.Chem.Soc., _ , 94 (1959)-(6) Production of the compound (XV) from thecompound (XIV) The compound (XIV) is reduced with 5 to 15 equi-valent amounts of iron powder in a solvent at a temperature of 60 to 150C to give the compound (XV). As the solvent, there may be employed an aliphatic carboxvlic acid (e.g.
acetic acid, propionic acid), if necessary, with an ester (e.g. ethyl acetate), an alcohol (e.g. methanol, ethanol, isopropanol) or water.

After completion of the reaction, the reaction mixture is subjected to ordinary post-treatment such as extraction with an organic solvent and concentration. When desired, purification by recrystallization or chromatography may be also adopted.
(7) Production of the compound (n = 1) from the compound (XV) The compound (n c 1) is obtainable by react-ing the compound (XV) with 1.0 to 2.0 equivalents of the compound (V) in the presence of 1.0 to 1.5 equivalents of a dehydrohalogenating agent in a solvent at a temperature of 0 to 80C, preferably at 10 to 30C. Examples of the solvent are aromatic hydrocarbons (e.g. toluene, benzene), amides (e.g. N,N-dimethylformamide), sulfur compounds (e.g.
dimethylsulfoxide), nitriles (acetnitrile), water and their mixtures. As the dehydrohalogenatins agent, there may be employed sodium hydride, sodium hydroxide, potassium hydroxide, etc.
After completion of the reaction, the reaction mixture is subjected to ordinary post-treatment such as addition of water, extraction with an organic solvent and concentration. When desired, purification by recrystal-lization or chromatography may be also adopted.
The compounds (I), (III), (IV) and (XV) are novel and can be summarized by the formula:

~ 19 -R3~1 ~ ~ (XVI) 11 ' wherein A is an amino group or a nitro group and Rl, R2, R3 and X are each as defined above.
Further, the compound (X) wherein X is a fluorine atom is also novel and may be representable by the formula:

~C)~ O ~ F

N (XVII) wherein R2 and R3 are each as defined above.
Typical examples for production of the starting compounds are illustratively shown in the following Examples.
Example 4 Production of the compound from the compound (IV):-Electrolytic iron (11.39 g) was suspended in 5%
aqueous acetic acid solution (22 ml) and heated to 80C.
To the suspension, a solution of 5-nitro-3-(2-propynyl)-3H-benzoxazol-2-one (4.15g) in acetic acid (20 ml) and ethyl acetate (20 ml) was dropwise added, and the resultant mixture was stirred at 70C for 3 hours. After being allowed to cool, water was added to the mixture, which was then extracted with ethyl acetate. The extract was washed 1~ ~4;~

( with water and sodium bicarbonate solution, dried anà
concentrated to give S-amino-3-(2-propynyl)-3H-kenzoxazol-2-one (1.95 g). m.p., 102.1C.
H-NMR (CDC13) ~ ppm: 2.32 tlH, t), 3.2 - 3.8 (2H, broad), 4.47 (2H, d), 6.7 - 7.2 (3H, m).
Example 5 Production of the compound from the compound (IV):-A solution of 2-methyl-6-nitro-4-(2-propynyl)-2~-1,4-benzoxazin-3(4H)-one (5 g) in acetic acid (S0 ml) and ethyl acetate (50 ml) was dropwise added to a mixture of iron powder (6 g) and S ~ aqueous acetic acid (50 ml), and the resultant mixture was heated under reflux for 1 hour.
After being allowed to cool, iron powder was removed by filtration and the filtrate was admixed with water. The aqueous layer was extracted with ethyl acetate, and the extract was combined with the organic layer, washed with a saturated sodium bicarbonate solution, dried and concen-trated. The residue was crystallized from methanol to give 6-amino-2-methyl-4-(2-propynyl)-2H-1,4-ben~oxazin-3(4H)-one (2.2 g). m.p., 158 - 159C.
lH-NMR (CDC13) ~ ppm: 1.5 (3H, d), 2.2 (lH, t), 3.8 (2H, m, NH2).
Example 6 Production of the compound from the compound (IV) -Iron powder (1.05 g) was suspended in 5 % aqueousacetic acid (2.0 ml) and heated ~o 80C. To the suspensioll, 1~4;~

a solution of 7-fluoro-6-nitro-4-(2-propynyl)-2H-1,4-benz-oxazin-3(4H)-one (0.47 g) in acetic acid (1.9 ml) and ethyl acetate (1.9 ml) was dropwise added, and the resultant mixture was heated under reflux at 60 to 80C for 3 hours.
Arter being allowed to cool, water and ethyl acetate were added to the mixture. The residue was removed by filtr-ation, and the filtrate was extracted with ethyl acetate.
The extract was washed with water and aqueous sodium bi-carbonate solution, dried and concentrated to give 6-amino-7-fluoro-4-(2-propynyl)-2H-1,4-benzoxazin-3(4H)-one (0.31 g). m.p., 183 - 185C.
H-NMR (CDC13 + DMSO-D6) ~ ppm: 2.60 (lH, t), 4.0 - 4.6 (2H, broad), 4~48 (2H, s), 4.58 (2H, d), 6.64 (lH, d, J = 10 Hz), 6.70 (lH, d, J = 6 Hz).
In the same manner as above, there are produced the compounds (III), of which typical examples are shown in Table 2.

12~i~;3;~

Table 2 2~ ~ X

n R1 R2 3 Physical constant i . --0 CH-CCH2- H m.p. 102.1C
1 CH3 H H H m.p. 152-153.5C
1 C2H5 H H H m.p. 118-119C
jl C2H5 H H F m.p. 108.5-109.0C
jl C2H5OCH2 H H F m.p. 133C
1 CH - CCH2- H H F m.p. 183-185C
1 CH-CCH2- CH3- H H m.p. 158-159C
1 CH-CCH2- CH3- H F m.p. 154.7C
1 CH_CCH2- C2H5- H H m.p. 126.5-128C
1 CH_CCH2- CH3- CH3 H m.p. 89-91C
1 CH-CCH - C2H5- H F m.p. 121-122.5C
1 CH-CCH2- CH3- CH3 F m.p. 106-107C
1 CH-CCH2- n C3H7 H m.p. 124.5-125.5C

~C=C~ H H H m.p. 97.5-99.5C

~C=C~ H H H m.p. 137.5-138.5C

¦ \C=C/ 2 H H F m.p. 133-134C

1~4;~
- ~3 -( (Continued) n Rl R2 R_ X Physical constant ¦

1 ~ H H F m.p. 109.5-110.5C !

Cl/ Cl 1 /CH~- H H H m.p. 142-143C
. CH2=C~Cl 1 CH C/CH2 H H F m.p. 108-109C

1 CH_CCH2- ~ H H m.p. 168-170C

1 CH3(Cl)C=CHCH2- H H H m.p. 113-115C
1 CH3(cl)c=cHcH2- H H F nD4 0 1.5848 1 ClCH=CHCH2- H H H m.p. 102-104C
1 ClCH=CHCH2- H H F m.p. 138-139C
1 C12C=CHCH2- H H H resinous 1 C12C=CHCH2- H H F m.p. 81.5-82C
1 BrC_CCH2- H H H m.p. 126.5-127.5C
1 BrC-CCH2- H H F m.p. 13q.5-140.5C

Example 7 Production of the compound (IV) from the compound (III):- -A suspension of sodium hydride (0.06 g) in N,N-dimethylformamide (3 ml) was cooled to 0C. 7-Fluoro-6-nitro-2H-1,4-benzoxazin-3(4H)-one (0.57 g) was added thereto at 0 to 5C, and the resultant mixture was stirred for 30 minutes. Propargyl bromide (0.35 g) was added to the mixture, which was gradually heated to room temperature, and i4;~
~4 -the reaction was continued for 6 hours. After addition of water, the resultant mixture was extracted with ethyl acetate, and the extract was washed with water, dried and concentrated. The residue was purified ~y silica gel thin layer chromatography using a mixture Oc ethyl acetzte and n-hexane (1 : 1 ) as an eluent to give 7-fluoro-6-nitro-4-(2-propynyl)-2H-1,4-benzoxazin-3(4H)-one (0.47 g). m.p., 109.1C.
lH-NMR (CDC13) ~ ppm: 2.42 (lH, t), 4.75 (2H, d), 4.79 (2H, s), 6.94 (lH, d, J = 10 Hz), 7.95 (lH, d, J = 6 Hz).
In the same manner as above, there are produced the compound (IV), of which typical examples are shown in Table 3.
Table 3 ~ IN ~ /Xo2 (IV) n Rl R2R3 X Physical constant 0 CH3 H m.p. 120.8C

1 CH3 H H H m.p. 189-191C
1 C2H5 H H H m.p. 130-131C
1 n3 7 H H H m.p. 72-73.5C
1 C2H5 H H F m.p. 131.6C
1 n3 7 H H F m.p. 103.7C

l;~tj4;3~;~
- ~s -( (Continued) n Rl R2 R3 X Physical constant ¦
1 CH-CCH2- H H F m.p. 109.1 a C
2 5 2 H H F m.p. 101.6C
1 CH-CCH2- CH3- H F resinous 1CH-CCH2- C2H5- H H n22.6 1 5626 1CH_CCH2- CH3- CH3 H n22.6 1 5630 1CH_CCH2- C2H5- H F n23-8 1 5661 1CH-CCH2- CH3- CH3 F m.p. 105.3aC
1CH-CCH2- 3 7 H H m.p. 124.5-125.5C
1 CH=CCH2- H ~ Cl m.p. 157.4C
1CH-CCH2- ~ H H n24-2 1 5967 C=C\ H H H n24.2 1 5819 C=C\ H H F n24.2 1.5926 /C=C\ H H H m.p. 97.5-99.5C

1H\C c/CH2~ H H F m.p. 125-126C
Cl/ \Cl 1/CH2- H H H m.p. 110-111C
CH2=C\
2 \Cl H H F m.p. 106-107C

1ClCH2CH=CHCH2- H H H n26.4 1 6068 1ClCH2CH=CHCH2- H H F n26.4 1 5870 ~tj4;~
- 26 ~

( (Continued) _ .
n Rl R2 3 Physical constant 1 BrCH2CH=CHCH2- H H H m.p. 81.5-83C
1 ~rCH2CH=C~CH2- H H F m.p. 108-109C
1 CH3(cl)c=cHcH2- H ~ H m.p. 117-118C
1 CH3(cl)c=cHcH2- K H F m.p. 113-115C
1 ClCH=CHCH2- H H ~ m.p. 103.5-105C
1 ClCH=CHCH2- H H F m.p. 67-69C
1 C12C=CHCH2- H H H m.p. 80-82C
1 C12C=CHCH2- H H F m.p. 83.5-85.5C
1 BrC-CCH2- H H H m.p. 115.5-117C
1 BrC-CCH2- H H F m.p. 152-153C

ExamDle 8 Production of the compound (III) from the compound (VIII):-A solution of 6-fluoro-2(3H)-benzoxazolone (1.0 g) in 80 % aqùeous sulfuric acid (6.5 g) was cooled to 0 IO
5C, and 60 % nitric acid (0.8 g) was gradually added thereto at 0 to 5C. The resultant mixture was stirred at the same temperature for 30 minutes and poured onto ice water. The precipitated crystals were collected by filtr-ation, washed with water and dried to give 6-fluoro-5-nitro-2(3H)-benzoxazolone (1.1 g). m.p., 175.4C.
H-NMR (CDC13 + DMSO-D6) ~ ppm: 4.0 (lH, broad), 6.8 - 7.9 ~3H, m~.
Example 9 Production of the compound (III) from the compound X) :-A solution of 7-fluoro-2H-1,4-benzoxazin-3~4H)-one (2.0 g) in 80 % aqueous sulfuric acid (30 ml) was cooled to 0 to 5C, and 60 ~ nitric acid (1.6 g) was gradually added thereto at 0 to 5C. The resultant mixture was stirred at the same temperature for 30 minutes and poured onto ice water. The precipitated crys~als were collected by filtr-ation, washed with water and dried to give 7-fluoro-6-nitro-2H-1,4-benzoxazin-3(4H)-one (2.1 g) as pale brown crystals. m.p., 205.9C.
1H-N~R (CDC13 + DMSO-D6) ~ ppm: 3.2 (lH, broad), 4.62 (2H, s), 6.76 (lH, d, J = 10 Hz), 7.6 (lH, a, J = 6 Hz).
In the same manner as above, there are produced the compounds (III), of which typical examples are shown in Table 4.
Table 4 ~ ~ (III) H
n R2 ~3 X Physical constant 0 F m.p. 175.4C
1 H H F m.p. 205.9C
1 CH3- H F m.p. 233.6C
1 C2H5- H H m.p. 138-139C
1 CH3- CH3- H m.p. 162C

1~i4~
- ~8 -(Continued) ~ . , n 2 _ 3 X Physical constant 1C2H5- ~ F m.p. 149-151C

¦1 CH3- CH3- F m.p. 134.5-136C

1 3 2 2 H H m.p. 165-167C

1 (CH3)2CH- H H m.p. 120C

1 3 2 2 H F m.p. 164-165C

1 ~ H H m.p. 148-150C

1 ~ H F m.p. 135.5-137C

ExamPle 10 Production of the compound (X) from the compound (IX):-Iron powder (36.42 g) was suspended in 5 % aqueousacetic acid (69 ml) and heated to 80C. To the suspension, a solution of ethyl 5-fluoro-2-nitrophenoxyaceta~e (15.86 g) in acetic acid (65-ml) and ethyl acetate (65 ml) was drop-wise added, and the resultant mixture was heated at 60 to 80C under reflux for 3 hours. After removal of residue by filtration, the filtrate was extracted with ethyl acetate.
The extract was washed with water and sodium bicarbonate solution, dried and concentrated to give 7-fluoro-2H-1,4-benzoxazin-3(4H)-one (6.82 g). m.p., 186.7C.
H-NMR (CDC13 + DMSO-D ) ~ ppm: 4.2 (lH, broad), 4.51 t2H, s), 6.5 - 7.0 (3H, m).
In the same manner as above, there are produced ( the compound ~X), o~ which typical examples are shown in Table 5.
Table 5 R2 ~ ~ F

R3 ~ (X~
O~\N /~/

R2 R3 Physical constant H H m.p. 186.7C
CH3 H m.p. 151.3C
C2H5 H m.p. 121-123C
CH3 CH3 m.p. 133-134C
n C3H7 H m.p. 99-101C

H m.p. 153-155C

Example 11 Production of the compound (XV) from the compound (XIV):-A mixture of iron powder (2.4 g) in acetic acid (1g) and water (20 ml) was refluxed, and a solution of methyl 2,4-dinitrophenoxacetate (2.24 g) in ethanol (20 ml~ and ethyl acetate (10 ml) was dropwise added thereto. The resultant mixture was stirred for 1 hour and concentrated under reduced pressure to evaporate ethanol. To the residue, water and ethyl acetate were added, and extraction was carried out. The organic layer was dried and concen-trated, and the residue was combined with ether. The ;3;~
- 30 ~

( precipitated crystals were collected by filtration to give 6-amino-2H-1,4-benzoxa~in-3(4H~-one (1.1 g).
lH-NMR (DMS0-d ) ~ ppm: 4.3 (2H, m, NH2), 4.4 (2H, s), 6.25 (lH, d, d), 6.3 (lH, d), 6.7 (lH, d), 10.3 (lH, m, -CNH).

Example 12 Producticn of the compound from the compound (XV):--Sodium hydride (0.08 g) was suspended in dry N,N-dimethylformamide (3 ml), and the suspension was cooled to 0C. While stirring, 6-amino-2H-1,4-benzoxa~in-3(4H)-one (0.5 g) was portionwise added to the suspension at 0C, and the resultant mixture was stirred at the same tempeature for 30 minutes. To the mixture, propargyl chloride (0.25 g) was dropwise added, and the mixture was stirred at room temper-ature for 6 hours. Water was added to the reaction mixture, which was then extracted with ethyl acetate. The extract was washed with water, dried and concentrated to give 6-amino-4-(2-propynyl)-2H-1,4-benzoxazin-3(4H)-one (0.36 g).
m.p., 260.1C.

1~4;3~;~

( On the practical usage of the tetrahydrophthal-imides (II),they may be applied in any preparation form such as emulsifiable concentrates, wettable powders, suspensions, granules, etc. in combination with conventional solid or liquid carriers or diluents as well as surface active agents or auxiliary agents.
~ he content of the tetrahydrophthalimides(II) as the active ingredient in such formulation form is usually within a range of 0.05 to 90 % by weight, preferably of 0.1 to 80 ~ by weight.
Examples of the solid carrier or diluent are fine powders or granules of kaolin clay, attapulgite clay, bentonite, terra alba, pyrophyll-ite, talc, diatomaceous earth, calcite, walnut powders, urea, ammonium sulfate and synthetic hydrous silicate, etc. As the liquid carrier or diluent, there may be exemplified aromatic hydrocarbons (e.g. xylene, methylnaphthalene), alcohols (e.g. iso-propanol, ethylene glycol, cellosolve), ketones (e.g.
acetone, cyclohexanone, isophorone), soybean oil, cotton seed oil, dimethylsulfoxide, N,N-dimethylformamide, aceto-nitrile, water, etc.
The surface active agent used for emulsification, dispersion or spreading may be any of the anionic and non-ionic type of agents. Examples of the surface active agent include alkylsulfates, alkylarylsulfonates, dialkyl-sulfosuccinates, phosphates of polyoxyethylenealkylaryl ethers, polyoxyethylene alkyl ethers, polyoxyethylene al~ylaryl ethers, polyoxvethylene polyoxypropylene block ~f~

copolymer, sorbitan fatty acid esters, polyoxyeth~lene sorbitan fatty acid esters, etc. Examples of the auxiliary agents include ligninsulfonates r sodium alginate, polyvinyl alcohol, gum arabic, CMC (carboxymethyl cellulose), PAP
(isopropyl acid phosphate), etc.
Practical embodiments of the herbicidal composi-tion according to the invention are illustratively shown in the following examples wherein parts are by weight. The compound number of the active ingredient corresponds to the one in Table 1.
Formulation Example 1 Fifty parts of Compound No. 1, 15 or 20, 3 parts of calcium ligninsulfonate, 2 parts of sodium laurylsulfate and 45 parts of synthetic hydrous silicate are well mixed while being powdered to obtain a wettable powder.
Formulation Example 2 Five parts of Compound No. 5, 9, 13 or 21, 14 parts of polyoxyethylenestyrylphenyl ether, 6 parts of calcium dodecylbenzenesulfonate, 30 parts of xylene and 45 parts of isophorone are well mixed while being powdered to obtain an emulsifiable concentrate.
Formulation Exam~le 3 Two parts of Compound No. 4, 10 or 20, 1 part of synthetic hvdrous silicate, 2 parts of calcium lignin-sulfonate, 30 parts of bentonite and 65 parts of kaolin clay are well mixed while being powdered. The mixture is then kneaded with water, granulated and dried to obtain granules.

Formulation Example 4 4;3;~;~

Twenty-five parts of Compound No. 2, 15 or 22 is mixed with 3 parts o~ polyoxyethylene sorbitan mono~leate, 3 parts of carboxymethyl cellulose and 69 parts of water and pulverized until the particle size of the mixture becomes less than 5 microns to obtain a suspension.
Formulation Example S
Five parts of Compound No. 2, 5, 9, 13, 15, 16, 20, 21 or 25, 14 parts of polyoxyethylènestyrylphenyl ether, 6 parts of calcium dodecylbenzenesulfonate, 30 parts of xylene and 45 parts of N,N-dimethylformamide are well mixed while being powdered to obtain an emulsifiable concentrate.
Formulation Example 6 Eighty parts of Compound No. 2, 16, 22 or 50, 3 parts of calcium ligninsulfonate, 2 parts of sodium lauryl-sulfate and 15 parts of synthetic hydrous silicate are well mixed while being powdered to obtain a wettable powder.
Formulation Example 7 0.1 Part of Compound No. 10 or 15, 0.9 part of synthetic hydrous silicate, 2 parts of calcium lignin-sulfonate, 30 parts of bentonite and 67 parts of kaolin clay are well mixed while being powdered. The mixture is then kneaded with water, granulated and dried to obtain granules.
The tetrahydrophthalimides (II) thus formulated in any suitable formulation form are useful for the pre-emergence or post-emergence control of undesired weeds by soil or foliar treatment as well as flood fallowing treatment. These treatments include the application to the soil surface prior to or after the transplanting or the 1~43~3 ( incorporation into the soil. The foliar treatment may be effected by spraying the herbicidal composition containing the tetrahydrophthalimides tII) over the top of the plants.
It may also be applied directly to the weeds if care is taken to keep the chemical of the crop foliage.
The tetrahydrophthalimides (II) of the invention may ~e used togéther with other herbicides to improve their activity as herbicides, and in some cases, a synergistic effect can be expected. Further, they may be applied in combination with insecticides, acaricides, nematocides, fungicides, plant growth regulators, fertilizers, soil improvers, etc.
Furthermore, the tetrahydrophthalimides (II) can be used as herbicides applicable to agricultural plowed field as well as paddy field. They are also useful as herbicides to be employed for orchard, pasture land, lawn, forest, non-agricultural field, etc.
~ he dosage rate of the tetrahydrophthalimides (II) may vary on prevailing weather conditions, formulation used, prevailing season, mode of application, soil involved, crop and weed species, etc. Generally, however, the dosage rate is from 0.02 to 100 grams, preferably from 0.05 to 50 grams, of the active ingredient per are. The herbicidal composi-tion of the invention formulated in the form of an emulsi-fiable concentrate, a wettable powder or a suspension may ordinarily be employed by diluting it with water at a volume of 1 to 10 liters per are, if necessary, with addition of an auxiliary agent such as a spreading agent. Examples of the ~4;3;~3 - 3s -( spreading agent include, in addition to the surface active agents as noted above, polyoxyethylene resin acid (ester), ligninsulfonate, abietylenic acid salt, dinaphthylmethane-disulfona'e, paraf,in, etc. The composition formulated in the form of granules may be normally applied as such withollt dilution.
The biological data of the tetrahydrophthalimides (II) as herbicides will be illustratively shown in the following Examples wherein the phytotoxicity to crop plants and the herbicidal activity on weeds were observed visually as to the degree of germination as well as the growth inhibition and rated with an index 0, 1, 2, 3, 4 or 5, in - which the numeral "O" indicates no material difference is seen in comparison with the untreated plant and the numeral "S" indicates the complete inhibition or death of the test plants.
The compounds shown in Table 6 below were used for comparison.
Table 6 Compound No. Chemical structure Remarks A O U.S. patent ll 3,878,224 CH30 ~ ~

B C1 Commercially ~ A available C14/ \ ~ O ~/ \~N02 herbicide;
\==~ "chloro-\Cl nitrofen"

1~;4~

Compound ~o. Chemical structure Remarks C O Cor~ercially ~S ¦¦ / H available N-c-N herbicide;
i~, JN I \ CH3 "metabenz-CH3 th.iazuron"

D O Commercially ~ 1 / CH3 available Cl~/ \~NH-C-N herbicide;
Cl ~ ~ OCH3 "linuron"

Test Example 1 Cylindrical plast-c pots (diameter, 10 cm; height, 10 cm) were filled with upland field soil, and the seeds of Japanese millet, tall morningglory and velvetleaf were sowed therein and covered with soil. A designed amount of the test compound formulated in an emulsifiable concentrate according to Formulation Example 2 or 5 was diluted with water, and the dilution was sprayed onto the soil surface by means of a small hand sprayer at a spray volume of 10 liters per are. The test plants were further grown in a greenhouse for 20 days, and the herbicidal activity was examined.
The results are shown in Table 7.

1~4~

( Table 7 pound ¦ Dosage Herbicidal activity No. (giare) I
i Japanese Tall morning- I Velvet-' millet glory ;leaf i l 20 ' 5 1 5 5 ! lo 4 ~ S 5 3 1200 45 S . 55 i 5 S 5 6 20 5 5 . 5 7 . 20 5 5 ~' 5 11 20 5 5 ~ 5 .~ `D D D D

, ~L ~

( (Continued) Compound Dosage Herbicidal activity No. (~/are) I _ Japanese Tall morning- Velvet-_ mlllet glory leaf 3~ ~ e 3 5 5 .

48 10 _ 5 5 49 20 5 5 s5 A Z0 _ _ 0 _ Test Example 2 Cylindrical plastic pots (diameter, 10 cm; height, 10 cm) were filled with upland field soil, and the seeds of Japanese millet, radish and velvetleaf were sowed therein and cultivated in a greenhouse for 10 days. A designed amount of the test compound formulated in an emulsifiable concentrate according to Formulation Example 2 or 5 was diluted with water containing a spreading agent, and the dilution was sprayed over the foliage of the test plants by means of a small hand sprayer at a spray volume of 10 liters per are. The test plants were further grown in the greenhouse for 20 days, and the herbicidal activity was examined.
The results are shown in Table 8.

1~i43X~

( Table 8 Compound Dosage Herbicidal activity No. (g/are) Japanese Radish Velvetlea millet 2 1 5 5 ~ 5 ~ 5 ! 3 1 5 4 S 5 6 5 4 i, 5 1 5 . 9 5 4 , 5 5 i 10 5.5 5 i 5 55 ! 1l 2.5 4 i 55 5 .' 13 5 4 5 5 ~ 14 ~' 2.5 4 s5 5 4~

( (Continued) Compound Dosage Herbicidal activity No. (g/are) Japanese Radish Velvetleaf !
millet i 34 S -i 36 5 _ 5 5 ! 40 5 _ 45 5 2.5 0 0 Test Example 3 Cylindrical plastic pots (diameter, 8 cm; height, 12 cm) were filled with paddy field soil, and the seeds of barnyardgrass (Echinochloa orYzicola) and broad-leaved weeds (e.g. common falsepimpernel, indian toothcup, waterwort) were sowed in 1 to 2 cm depth. Water was poured therein to make a flooded condition, and rice seedlings of the 2-leaf stage were transplanted therein and grown in a greenhouse.
Six days (at that time the weeds began to germinate) there-after, a designed amount of the test compound formulated in an emulsifiable concentrate according to Formulation Example 2 or 5 and diluted with water (5 ml) was applied to the pots by perfusion. The test plants were grown for further 20 i4;~

days in the greenhouse, and the herbicidal activitv was examined.
The results are shown in Table 9.
Table 9 Compound Dosage Herbicidal activity No. (g/are) _ Rice plant Barnyard- Broad-leaved grass weed 31 10 1 ~ 2 Test Example 4 Vats ~33 cm x 23 cm x 11 cm) were filled with upland field soil, and the seeds of soybean, peanut, corn, common cocklebur, tall morningglory, velvetleaf, redroot pigweed, black nightshade, barnyardgrass and green foxtail were sowed therein to 1 to 2 cm depth. A designed amount of the test compound formulated in an emulsifiable concentrate according to Formulation Example 2 or 5 was diluted with water, and the dilution was sprayed onto the soil surface by means of a small hand sprayer at a spray volume of 10 liters per are. The test plants were further grown in a greenhouse 4;~

( for 20 days, and the herbicidal activity was examined.
The results are shown in Table 10.

l~tj4;~

~ r~ . g Ul ~ W ~ ~- O a~ O ~

- - c~ c ~3 r~ v~, ~ ~ ~ ~ ~ ~ U- ~n u. ~ ~n ~ ~ ~n P~ 5, ~
n r~ ~ ~_ n . _ O
. _ _ O O O O O ~-- O O O O O O O O O O O O O O O O ~ ~ ~ D
_ =~

o t~ ~ o ~ r~ O
--n o 3 ~3 :::

~ ~, ~ ~
n ~ n u~ n n o n I :~
_ o~

C~ o~
~ Vl ~ ~n ~ n ~ ~,n ~n ~n ~n ~n I I ~ ~ I ~ ~ ~ ~ ~ ~ ~n ~ ~ X n 1~4;~

w ::. ~ .~ æ ~ ¦
-.~

r ~ ~ ~n ~ o , (~
0000 0~0 1~1 o o o o o _ o :~

o o o o ~ I I 1- o n O O O O ~ n 3 ~ 3 ~t O O O O ~ ~ W 3 ~~~ ~ ~ W

O ~ O ~ ~ n = :~ W n Ol-o-- ~ n =,3~ c:

ol-o-- o~ I c, lc I

000_ ~n ~X13 _ - 45 _ 1~4~

( Test Example 5 Vats ~33 cm x 23 cm x 11 cm) were filled with upland field soil, and the seeds of wheat, barley, catchweed bedstraw, persian speedwell, common chickweed, common lambsauarters, pale smartweed, wild buckwheat and annual bluegrass were sowed therein to 1 to 2 cm depth. A designed amount of the test compound formulated in an emulsifiable concentrate according to Formulation Example 2 or 5 was diluted with water, and the dilution was sprayed onto the soil surface by means of a small hand sprayer at a spray volume of 10 liters per are. The test plants were further grown in a greenhouse for 27 days, and the herbicidal . .
activity was examined.
The results are shown in Table 11.

4;~

. . o o 3~ ~n ~ W O - O ~ C

, ~, ~ o ~ o ~ o ~- o ~ o l~ ~ g 1 ~n ~ ~ ~ ~n ~ ~ ~ ~ a~ ~ ~ ~ ~ ~n ~n ~n U~ O~ tO
~A ~ ~ ~ ~ 0~ ,_ oooo ooo I o~ooo 1 1-~oOOOO~O~ l ~
.

0000 000_ 1 1 0~ 00000l~ 1-. _ O O O O I tJl I lJ~ ~D

~ ID
0 0 0 0 ~ n ~ _ C n o rD
0 0 0 0 U~ n C r~

. ~ O n 0 0 0 ~_ ~ n U~ ~~ `C

O O O O ~ n ~
~ oc 1' 0 0 0 0 ~ n ~ ~
0~
O O O O I ~ ~ I C

1~4;~X;~

( Test Example 6 Vats (33 cm x 23 cm x 11 cm) were filled with upland field soil, and the seeds of corn, wheat, common cocklebur, velvetleaf, black nightshade, tall morningglory, common lambsquarters and green foxtail were sowed therein and cultivated for 18 days in a greenhouse. A designed amount of the test compound formulated in an emulsifiable concentrate according to Formulation Example 2 or 5 was diluted with water containing a spreading agent, and the dilution was sprayed over the foliage of the test plants by means of a small hand sprayer at a spray volume of 5 liters per are. The test plants were further grown in the green-house for 20 days, and the herbicidal activity was examined.
At the time of the application, the test plants were generally at the 1 to 4 leaf stage and in 2 to 12 cm height, although growing stage of the test plants varied depending on their species.
The results are shown in ~able 12.

_ o ~
y 3 n ~ w ~ ~ o a~ ul .P o ul ~ ~ ~a C

-~ 1 oooooooooooooooooooooooooo ~n ~D
.......................... ~
~-Wl-W~-WI-WI~ WI-WI-WI~ ~W~WI-W ~ ~D t-r~
f~ o l--o I o I l-- I o l--o ~ ~ I \~ I o ~--~ I
:~:
0 ~ 1- 1 0 1 1~ 1 ~ I0 1- ~- 1 tD

- n ~D O O

_~

~ ~
. _ 1~.

~a 3 ~3 ':
o~ ,..

LD4,3~

0~
l~ , o o ~Ul . . ~ ~
. ~ O
oooo ~ 9"9 ~ I_ :I:

O 1- 0 0 ~h ~ n o o o o ~ ~ ~

--~ ~ r .

~ f - 50 ~43 '~

( Test Example 7 Vats (33 cm x 23 cm x 11 cm) were filled with upland field soil, and the seeds of soybean, peanut, sickle-pod, hemp sesbania, velvetleaf, prickly sida, jimsonweed and large crabgrass were sowed therein to 1 to 2 cm depth. A
designed amount of the test compound formulated in an emulsifiable concen~rate according to Formulation Example 2 or S was diluted with water, and the dilution was sprayed onto the soil surface by means of a small hand sprayer at a spray volume of 10 liters per are. The test plants were further grown in a greenhouse for 21 days, and the herbi-cidal activity was examined.
The results are shown in Table 13.

- s ~ 4~

-- ~ ~ ,_ ~ a _ . P
, ~ ,~ o~ 0, c ~n ~ ~ ~ ~ P~ D~
Ul UIVUl ~5 ,a~ W

oo oooooo 3 00 ~ (3:

00 V~ n 3 3 3 O O ~ n ~ ~ ~ n O_ ~ n 33 O _ ~ n ~ O

O O _ D

- 52 1~i4;~

( Test Example 8 Seeds of wheat, catchweed bedstraw, common chick-weed, persian speedwell and common lambsquarters were sowed in the field as previously laid up in ridges and divided into plots of 4 m2. A designed amount of the test compound formulated into a wettable powder according to Formulation Example 1 was diluted with water and sprayed onto the soil surface by means of a small hand sprayer at a spray volume of 7.5 liters per are. The application was made with three replications. After cultivation for 39 days, the herbicidal activity on the weeds as well as the phytotoxicity on wheat were evaluated as follows: the aerial parts of the test plants were cut off and weighed (fresh weight) and growth inhibition rate was calculated based thereon according to the following equation:

Growth Fresh weight of test plants in inhibition = ( 1 - treated plot ) x 100 rate (%) Fresh weight of test plants in untreated plot The results are shown in Table 14.

- s3 ~ ;4~

able 14 Compound Dosage Growth inhibition rate (%) No. (g/are) Wheat Catch- Common Persian Common weea chick- speed- lambs-bed- weed well quarters, 2 8 95 95 lO0 95 2 9 98 lO0 100 100 1 4 93 g8 100 95 2 8 97 lO0 100 100 Test Example 9 Seeds of soybean, peanut, redroot pigweed, velvet-leaf, black nightshade and prickly sida were sowed in the field as previously laid up in ridges and divided into plots of 3 m2. A designed amount of the test compound formulated into an emulsifiable concentrate according to Formulation Example 2 or 5 was diluted with water and sprayed onto the soil surface by means of a small hand sprayer at a spray volume of 10 liters per are. The application was made with two replications. After cultivation for 40 days, the growth inhibition rate of the test plants was measured in the same manner as in Test Example 8.
The results are shown in Table 15.

4;~

- 5~1 -Table 15 Compound ~osage Growth inhibition rate (%) No. (g/are) Soy- Peanut Redroot Velvet- Black Prickly bean pigweed leaf night- sida shade _ 1 0 0100 75 100 lOO
0.5 0 0 90 26 93 65 2 3 ~100 100 100 100 I 0.5 0 0 96 78 100 85 _ 0.5 0 0 0 0 0 0

Claims (6)

Claims:

1. A compound of the formula (I):
(I) wherein R1 is a hydrogen atom, a C1-C5 alkyl group, a C3-C4 alkenyl group, a C3-C4 alkynyl group, a C1-C4 haloalkyl group, a C3-C4 haloalkenyl group, a C3-C4 haloalkynyl group, a C1-C2 alkoxy(C1-C2)alkyl group or a C1-C2 alkoxy(C1-C2)-alkoxy(C1-C2)alkyl group, R2 and R3, which may be the same or different, each represents a hydrogen atom, a halogen atom, a C1-C3 alkyl group or a phenyl group, X is a hydro-gen atom, a chlorine atom or a fluorine atom, n is an integer of 0 or 1 and A is an amino group or a nitro group.

2. The compound according to claim 1, wherein X
is a fluorine atom.

3. The compound according to claim 1, wherein R1 is a C3-C4 alkenyl group or a C3-C4 alkynyl group, R2 is a hydrogen atom or a methyl group, R3 is a hydrogen atom, X is a hydrogen atom or a fluorine atom and n is 1.

4. The compound according to claim 1, wherein R1 is a hydrogen, R2 is a hydrogen atom or a methyl group, R3 is a hydrogen atom, X is a hydrogen atom or a fluorine atom, n is 1 and A is an amino group.

5. The compound according to claim 1, wherein R1 is a hydrogen, R2 is a hydrogen atom or a methyl group, R3 is a hydrogen atom, X is a fluorine atom, n is 1 and A
is an amino group.

6. The compound according to claim 1, wherein R1 is a hydrogen, R2 is a hydrogen atom or a methyl group, R3 is a hydrogen atom, X is a fluorine atom, n is 1 and A is a nitro group.