Tetrahydrotriazines for aquatic herbicidal use

Aquatic herbicidal compositions including tetrahydrotriazine compounds as the active toxicant. The invention also covers a method for the control of aquatic plant life which method utilizes as the active ingredient a tetrahydrotriazine compound.

This invention relates to aquatic herbicides and more particularly to 
herbicides employed for the control of aquatic weeds. 
Aquatic plants cause a variety of problems in lakes, pools, streams, 
irrigation systems, drainage canals, and in the cultivation of certain 
field crops. Thus in the recreational uses of water, aquatic plants 
interfere with swimming and fishing, foul outboard motors and often impart 
undesirable flavors and odors to the water. In streams, irrigation 
systems, and drainage canals, aquatic plants interfere with the flow of 
water, effect increased evaporation and seepage, and cause clogging of 
structures; while in the cultivation of such field crops as rice, aquatic 
plants compete for soil nutrients and sunlight resulting in considerable 
reductions of yields. While many mechanical methods for the control of 
undesirable aquatic plant life have been proposed and used in the past, 
such as dredging, underwater mowing, hand cleaning and chaining, only 
partial success has been obtained. In recent years there has been an 
increased interest in the chemical control of aquatic plants and as a 
result a few chemical compounds which are effective in controlling some of 
the undesirable aquatic plants have been discovered. 
It is surprising, however, in view of the vast number of herbicidally 
active compounds which are known, only a limited number of chemical 
compounds exhibiting activity towards aquatic plant life have been found. 
In a study by Frank et al. 1963 Weeds 11:124-228, wherein ninety-one 
herbicides were tested for aquatic activity, it was found that little or 
no correlation between herbicidal activity toward terrestrial vegetation 
and activity for the control of aquatic plant life exists. 
In addition, the use of herbicides for the control of aquatic weeds poses 
some unique problems due in part to differences in plant morphology and in 
part to the differences in the plant environment. When trees, brush and 
other terrestrial weeds are sprayed with herbicide, relatively large 
quantities of the herbicide-spray actually contact the foliage, stem and 
in some cases the roots (i.e., following precipitation). A similar direct 
application of herbicide spray to the exposed portion of aquatic 
vegetation is possible and for some weeds this is enough since the 
translocation process carries the herbicide throughout the plant. On the 
other hand for the submersed weeds and for the parts of the other weeds 
under the surface of the water the physical problem of carrying the 
herbicide directly to the plant without great dilution in a large mass of 
water is much greater than for the land weeds. Another problem is caused 
by differences in the plants themselves; a number of aquatic weeds such as 
the water hyacinth, pond lily, etc., are covered with a waxy coat which is 
only slightly permeable to aqueous solutions. Some of the other weeds such 
as elodea are highly permeable and nearly anything soluble in water can 
get into the plant. In selecting a herbicide, a formulation and an 
application method, one should consider all these factors in order to 
optimize the opportunity for the herbicide to be absorbed the the plant. 
In view of the aquatic weed problem and the limited development of chemical 
compounds which can be used to control such weeds it is readily apparent 
that additional compounds and compositions useful for this purpose are 
urgently required. 
In accordance with the present invention there is provided an aquatic 
herbicidal composition comprising an acceptable carrier and as an active 
toxicant a herbically effective amount of a compound selected from the 
group consisting of compounds having the general formula: 
##STR1## 
wherein 
R.sup.1 is hydrogen, lower alkyl (C.sub.1 -C.sub.6), cycloalkyl (C.sub.3 
-C.sub.7), lower alkenyl (C.sub.2 -C.sub.6), lower alkynyl (C.sub.3 
-C.sub.6), haloalkyl (C.sub.1 -C.sub.6) and alkoxyalkyl (C.sub.2 
-C.sub.6); 
R.sup.2 and R.sup.3 individually are hydrogen, ketoalkyl (C.sub.3 
-C.sub.5), lower alkyl (C.sub.1 -C.sub.6), cycloalkyl (C.sub.3 -C.sub.6), 
alkoxyalkyl (C.sub.2 -C.sub.4), alkenyl (C.sub.2 -C.sub.6), haloalkyl 
(C.sub.1 -C.sub.6), and acyl (C.sub.2 -C.sub.4); R.sup.2 and R.sup.3 taken 
together can also form a spirocyclic ring of C.sub.3 -C.sub.5 carbon 
atoms; 
R.sup.4 individually can be hydrogen, alkyl (C.sub.1 -C.sub.6), a maximum 
of two halogens selected from the group consisting of Cl, F, and Br, 
alkoxyl (C.sub.1 -C.sub.4), nitro, alkylthio (C.sub.1 -C.sub.4) and 
alkylsulfonyl (C.sub.1 -C.sub.4 ); 
R.sup.5 may be hydrogen, carbamoyl, N-alkylcarbamoyl (C.sub.2 -C.sub.14), 
N-arylcarbamoyl, N-(substituted aryl)carbamoyl, N-haloalkylcarbamoyl 
(C.sub.2 -C.sub.12), N-carboalkoxyalkylcarbamoyl, N-carboxyalkylcarbamoyl 
(C.sub.3 -C.sub.14), N-alkoxyalkylcarbamoyl (C.sub.3 -C.sub.14), 
N-arylsulfonylcarbamoyl, acyl(C.sub.1 -C.sub.14), aroyl, substituted 
aroyl, alkoxycarbonyl (C.sub.2 -C.sub.14), aryloxycarbonyl, hydroxyacyl 
(C.sub.2 -C.sub.8), alkoxyacyl (C.sub.3 -C.sub.9), alkylthioacyl (C.sub.3 
-C.sub.9), alkylsulfonylacyl (C.sub.3 -C.sub.7), N,N-dialkylaminoacyl 
(C.sub.4 -C.sub.10), alkylsulfonyl (C.sub.1 -C.sub.14), haloalkylsulfonyl 
(C.sub.1 -C.sub.14), arylsulfonyl, substituted arylsulfonyl, alkyl 
(C.sub.1 -C.sub.14), hydroxyalkyl (C.sub.1 -C.sub.8), alkoxyalkyl (C.sub.2 
-C.sub.9), haloalkyl (C.sub.1 -C.sub.8), cycloalkyl (C.sub.3 -C.sub.7), 
alkenyl (C.sub.2 -C.sub.14), cycloalkenyl (C.sub.5 -C.sub.7), alkynyl 
(C.sub.2 -C.sub.14), aryl and substituted aryl. 
X is oxygen or sulfur. 
Compositions falling within the above generic formula exhibit biological 
activity as aquatic herbicides to a greater or lesser extent. Some exhibit 
very powerful herbicidal activity against aquatic plants in extremely 
small dosages while others require larger dosages to be effective. 
In general, the compounds which are preferred for aquatic herbicidal 
activity are those of the above structural formula wherein R.sup.1 is 
alkyl (C.sub.1 -C.sub.4); 
R.sup.2 and R.sup.3 individually are alkyl (C.sub.1 -C.sub.3) and 
cycloalkyl (C.sub.3 -C.sub.5); 
R.sup.4 is hydrogen and alkyl (C.sub.1 -C.sub.4); 
R.sup.5 is hydrogen, N-alkylcarbamoyl (C.sub.2 -C.sub.14), N-arylcarbamoyl, 
N-(substituted aryl)carbamoyl, acyl (C.sub.1 -C.sub.14), alkoxycarbonyl 
(C.sub.2 -C.sub.14), alkylsulfonyl (C.sub.1 -C.sub.14), arylsulfonyl and 
substituted arylsulfonyl. 
X is 0. 
Compounds which are most preferred are represented by structure and 
nomenclature as indicated below: 
##STR2## 
1,2-Dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]-benzimidazol-4(3H)-one 
(Compound 1) 
##STR3## 
1,2-Dihydro-2,2-dimethyl-3-ethyl-1,3,5-triazino[1,2-a]-benzimidazol-4(3H)- 
o 
ne (Compound 2) 
##STR4## 
1,2-Dihydro-2,3-dimethyl-2-ethyl-1,3,5-triazino[1,2-a]-benzimidazol-4(3H)-o 
ne (Compound 3) 
##STR5## 
4-Oxo-2,3,4,10-tetrahydro-N,2,2,3-tetramethyl-1,3,5-triazino[1,2-a]benzimi 
d 
azole-10-carboxamide (Compound 4) 
##STR6## 
2-Ethyl-4-oxo-2,3,4,10-tetrahydro-N,2,3-trimethyl-1,3,5-triazine[1,2-a]benz 
imidazole-10-carboxamide (Compound 5) 
##STR7## 
N-Ethyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]ben 
z 
imidazole-10-carboxamide (Compound 6) 
##STR8## 
N-Isopropyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino[1,2a] 
b 
enzimidazole-10-carboxamide (Compound 7) 
##STR9## 
N-Propyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]be 
n 
zimidazole-10-carboxamide (Compound 8) 
##STR10## 
N-tert-Butyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino[1,2- 
a 
]benzimidazole-10-carboxamide (Compound 9) 
##STR11## 
N-(4-Chlorophenyl)-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazin 
o 
[1,2-a]benzimidazole-10-carboxamide (Compound 10) 
##STR12## 
1,2-Dihydro-2,2,3,7,8-pentamethyl-1,3,5-triazino-[1,2-a]benzimidazol-4(3H) 
- 
one (Compound 11) 
##STR13## 
2,10-Dihydro-10-(ethoxycarbonyl)-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benz 
i 
midazol-4(3H)-one (Compound 12) 
##STR14## 
N-(3,4-Dichlorophenyl)-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-tri 
a 
zino[1,2-a]benzimidazole-10-carboxamide (Compound 13) 
##STR15## 
2,10-Dihydro-10-[(2-methyl)propanoyl]-2,2,3-trimethyl-1,3,5-triazino[1,2-a 
] 
benzimidazol-4(3H)-one (Compound 14) 
##STR16## 
2,2-Diethyl-N,3-dimethyl-4-oxo-2,3,4,10-tetrahydro-1,3,5-triazino[1,2-a]be 
n 
zimidazole-10-carboxamide (Compound 15) 
##STR17## 
2,10-Dihydro-10-(methylsulfonyl)-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benz 
i 
midazol-4(3H)-one (Compound 16) 
##STR18## 
1,2-Dihydro-2,2-dimethyl-1,3,5-triazino[1,2-a]-benzimidazol-4(3H)-one 
(Compound 17) 
##STR19## 
2,10-Dihydro-10-[(4-tolyl)sulfonyl]-2,2,3-trimethyl-1,3,5-triazino[1,2-a]b 
e 
nzimidazol- B 4(3H)-one (Compound 18) 
##STR20## 
N-Butyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]ben 
z 
imidazole-10-carboxamide (Compound 19) 
##STR21## 
2-Cyclopropyl-1,2-dihydro-2,3-dimethyl-1,3,5-triazino[1,2-a]benzimidazol-4 
( 
3H)-one (Compound 20) 
For convenience the R.sup.1 -R.sup.5 substituents of the preferred 
compounds within the generic formula are as indicated in the following 
Table I. 
TABLE I 
______________________________________ 
Com- 
pound R.sup.1 
R.sup.2 
R.sup.3 
R.sup.4 R.sup.5 
______________________________________ 
1 CH.sub.3 
CH.sub.3 
CH.sub.3 
--* -- 
2 C.sub.2 H.sub.5 
CH.sub.3 
CH.sub.3 
-- -- 
3 CH.sub.3 
CH.sub.3 
C.sub.2 H.sub.5 
-- -- 
4 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- CH.sub.3 NHCO 
5 CH.sub.3 
CH.sub.3 
C.sub.2 H.sub.5 
-- CH.sub.3 NHCO 
6 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- C.sub.2 H.sub.5 NHCO 
7 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- (CH.sub.3).sub.2 CHNHCO 
8 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- n-C.sub.3 H.sub.7 NHCO 
9 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- (CH.sub.3).sub.3 CNHCO 
10 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- 
##STR22## 
11 CH.sub.3 
CH.sub.3 
CH.sub.3 
7,8-(CH.sub.3).sub.2 
-- 
12 CH.sub.3 
CH.sub.3 
CH.sub. 3 
-- C.sub.2 H.sub.5 OCO 
13 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- 
##STR23## 
14 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- (CH.sub.3).sub.2 CHCO 
15 CH.sub.3 
C.sub.2 H.sub.5 
C.sub.2 H.sub.5 
-- CH.sub.3 NHCO 
16 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- CH.sub.3 SO.sub.2 
17 H CH.sub.3 
CH.sub.3 
-- -- 
18 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- 
##STR24## 
19 CH.sub.3 
CH.sub.3 
CH.sub.3 
-- n-C.sub.4 H.sub.9 NHCO 
20 CH.sub.3 
##STR25## 
CH.sub.3 
-- -- 
______________________________________ 
*--designates hydrogen 
In general, the novel tetrahydrotriazines of this invention can be prepared 
according to several methods illustrated by the following reaction 
schemes: 
##STR26## 
where X, and R.sup.1 -R.sup.4 are as described previously. 
A special case of Method I is that in which R.sup.1 =hydrogen and X=oxygen. 
In this case the isocyanic acid (HNCO) required for the second step is 
generated in situ by addition to the reaction mixture of 
N-chloroformamide, as shown below: 
##STR27## 
wherein Z may be halogen, perhalate (e.g. perchlorate, perbromate); X and 
R.sup.1 -R.sup.4 are as described previously; R may be lower alkyl 
(C.sub.1 -C.sub.3), aryl (e.g. phenyl or substituted phenyl), cycloalkyl 
(C.sub.3 -C.sub.7), or the two R groups taken together may be cyclic in 
nature. 
##STR28## 
wherein X and R.sup.1 -R.sup.5 are as defined previously; R.sup.6 may be 
alkyl (C.sub.1 -C.sub.14), aryl, substituted aryl, carboalkoxyalkyl, 
alkoxyalkyl, or hydrogen; R.sup.7 may be alkyl (C.sub.1 -C.sub.14), 
alkoxyalkyl, alkylthioalkyl, alkylsulfonylalkyl, dialkylaminoalkyl, aryl, 
cycloalkyl, substituted aryl, alkoxy (C.sub.1 -C.sub.14), aryloxy, 
substituted aryloxy; R.sup.8 may be alkyl (C.sub.1 -C.sub.14), aryl, 
substituted aryl; R.sup.9 may be alkyl (C.sub.1 -C.sub.14), alkoxyalkyl, 
alkylthioalkyl, alkylsulfonylalkyl, dialkylaminoalkyl, aryl, cycloalkyl 
(C.sub.3 -C.sub.7), alkenyl (C.sub.2 -C.sub.14), cycloalkenyl (C.sub.5 
-C.sub.7), alkynyl (C.sub.2 -C.sub.14); Y may be halogen (e.g. chlorine, 
bromine, iodine), arylsulfonate, alkylsulfonate. 
In general, Method I involves three steps in the procedure for obtaining 
the final product, i.e. step 1, which is a Schiff base-forming reaction; 
step 2 which is a ring forming reaction involving the Schiff base formed 
in step 1; and step 3 which is a thermal or hydrolytic cleavage step to 
form the tetrahydrotriazine. 
The step 1 Schiff base-forming reaction illustrated in Method I utilizes an 
appropriate substituted amine which is admixed with an appropriate ketone 
as indicated. The reaction is conducted in the presence of a solvent which 
advantageously can be the ketone reactant itself or alternatively the 
ketone can be employed with a cosolvent. Illustrative of solvents that can 
be utilized in the conduct of the Schiff base-forming reaction are 
tetrahydrofuran, dioxane and dimethoxyethane. The Schiff base-forming 
reaction step of Method I can be conducted in the temperature range of 
about 20.degree.-200.degree. C., preferably about 35.degree. C. to 
120.degree. C. and in the pressure range of one atmosphere up to that 
required to contain the reaction at about 200.degree. C. The concentration 
of the amine starting material in the mixture before reaction begins can 
be from 0.01 to 1.0 molar, preferably about 0.1 to 0.7 molar. In addition, 
the Schiff base-forming reaction step can, if desired, be conducted in the 
presence of an acid catalyst. Suitable acid catalysts include 
p-toluenesulfonic acid, trifluoroacetic acid, or zinc chloride. 
As will be observed from the reaction scheme illustrated in Method I, it is 
necessary to remove the water formed as a by-product in the reaction. 
Water can be removed from the reaction by adding a drying agent or water 
scavenger to the reaction mixture. Illustrative of drying agents which can 
be used include molecular sieves (3A, 4A and 5A), calcium sulfate, calcium 
chloride and magnesium sulfate. Water may also be removed from the 
reaction by azeotropic distillation using a suitable cosolvent, examples 
of which include benzene, toluene and xylene. The Schiff base formed in 
Method I can be isolated or alternatively it can be subjected to the 
ring-forming reaction (step 2) in situ. If the Schiff base is isolated, it 
is thereafter subsequently dissolved in a suitable solvent and is then 
subjected to the illustrated ring-forming reaction. Examples of suitable 
solvents for this purpose include tetrahydrofuran, acetone, dioxane, 
dimethoxyethane, chloroform and methylene chloride. The ring-forming step 
of Method I can be conducted using from two to ten molar equivalents of a 
suitable isocyanate or isothiocyanate based on the number of moles of 
starting amine employed. In general, the ring-forming reaction step is 
conducted at a temperature range of about 0.degree.-200.degree. C., 
preferably about 25.degree. to 80.degree. C., and in a pressure range of 
about one atmosphere up to that required to contain the reaction at 
200.degree. C. The cleavage step 3 illustrated in Method I can be 
accomplished either hydrolytically or thermolytically. When the 
thermolytic method is used, the cyclized material from step 2 is placed in 
a suitable solvent; the resulting mixture is thereafter heated and the 
cleaved isocyanate is distilled from the mixture. Illustrative of the 
solvents utilized for the thermal cleavage step include petroleum 
hydrocarbons, xylene, diglyme and dimethylsulfoxide. The thermolytic 
cleavage of R.sup.1 NCX may also occur during recovery of product from the 
ring-forming reaction (step 2) when, as may be practiced, the crude 
product is continually extracted with a hot inert solvent (such as hexane) 
as in a Soxhlet extraction system. Such a spontaneous thermolytic cleavage 
of R.sup.1 NCX during workup frequently results in isolation of the final 
cleavage product alone, or of mixtures of the final product with the 
10-N-carbamoylated precursor. The thermolytic reaction step 3 can be 
conducted at a temperature range of about 80.degree.-250.degree. C., 
preferably about 100.degree. to 180.degree. C., and in a pressure range 
of about 0.2-2.0, preferably 0.5 to 1.0 atmosphere. When the hydrolytic 
method is utilized, the cyclized material from step 2 is dissolved in a 
suitable solvent and the resulting solution is treated with water and an 
acid or base catalyst. Suitable solvents for the hydrolytic method include 
tetrahydrofuran, dioxane, acetone, dimethoxyethane and ethanol. Suitable 
acid catalysts include hydrochloric acid, sulfuric acid, trifluoroacetic 
acid and p-toluenesulfonic acid. Suitable base catalysts include sodium 
hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate or 
triethylamine. The hydrolytic method can be conducted in a temperature 
range of about 0.degree.-100.degree. C., preferably about 25.degree. to 
60.degree. C., and in the pressure range of one atmosphere up to that 
required to contain the reaction at 100.degree. C. 
The Schiff base-forming reaction illustrated in Method II can be conducted 
using a stoichiometric amount (i.e. one equivalent) of the iminium salt in 
a suitable solvent. Suitable solvents include tetrahydrofuran, dioxane, 
and dimethoxyethane. Alternatively, the Schiff base-forming reaction of 
Method II can be conducted using a catalytic amount of the iminium salt in 
an appropriate solvent. The appropriate solvent is the ketone R.sup.2 
COR.sup.3 or a mixture of this ketone and a suitable cosolvent. Suitable 
cosolvents include tetrahydrofuran, dioxane or dimethoxyethane. The Schiff 
base-forming reaction of Method II can be conducted in a temperature range 
of about 20.degree.-200.degree. C., preferably 35.degree.-100.degree. C., 
and in a pressure range of about 0.2 atmosphere up to that required to 
contain the reaction at about 200.degree. C. The concentration of the 
starting material (amine) in the mixture before reaction begins may be 
from 0.01 to 1.0, preferably 0.1 to 0.7 molar. The Schiff base formed in 
Method II can be isolated or alternatively subjected to the ring-forming 
step in situ. Conditions for reaction in the ring-forming step and the 
subsequent cleavage step are as discussed for Method I. 
The reaction illustrated by Method III represents the introduction of the 
substituent R.sup.5 (when R.sup.5 is other than hydrogen). This step can 
be conducted by combining the appropriate tricyclic material, obtained by 
Methods I and II, with the appropriate organic isocyanate, acyl halide, 
aroyl halide, sulfonyl halide or halide as defined previously in a 
suitable organic solvent in the presence of a suitable base catalyst or 
acid acceptor. Suitable organic solvents include acetone, tetrahydrofuran, 
dioxane, dimethoxyethane, methylene chloride and chloroform. Suitable 
catalysts or acid acceptors include triethylamine, pyridine, sodium 
carbonate, and potassium carbonate. The reaction may be conducted in the 
temperature range of 0.degree.-100.degree. C., preferably 25 to 50, and in 
the pressure range of 0.5-10.0, preferably 1 to 2 atmospheres. The 
concentration of the tricyclic material before reacton may be from 
0.01-1.0, preferably 0.05 to 0.5 molar. 
In general (for Methods I and II) the starting amines and their coreactants 
are known compounds or may be prepared through well-established chemical 
transformations. For example the 2-aminobenzimidazole reactant can be 
prepared by reaction of ortho-phenylenediamines with cyanamide according 
to the procedure of S. Weiss et al, Angewandte Chemie International 
Edition, Volume 12, page 841 (1973). 
The ketones can be prepared by oxidation of the corresponding secondary 
alcohols as described by Arnold P. Lurie in Kirk-Othmer Encyclopedia of 
Chemical Technology, Second Edition, Volume 12, page 125, John Wiley and 
Sons, New York. 
The following aquatic herbicidally active compounds are further 
illustrative of compounds within the purview of the above generic formula 
and which can be conveniently prepared by the methods of the invention 
simply by selecting appropriate reactants for use in the procedures 
described previously: 
7,8-Dichloro-4-oxo-2,3,4,10-tetrahydro-N,2,2,3-tetramethyl-1,3,5-triazino[1 
,2-a]benzimidazole-10-carboxamide 
1,2-Dihydro-8-nitro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H) 
-one 
4-Oxo-N,2,2,3,8-pentamethyl-2,3,4,10-tetrahydro-1,3,5-triazino[1,2-a]benzim 
idazole-10-carboxamide 
1,2-Dihydro-2,2,3,9-tetramethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-2,2,3,7-tetramethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
7,8-Dichloro-1,2-dihydro-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-3-isopropyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
2,2p-Diethyl-1,2-dihydro-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-2,3,7,8-tetramethyl-2-trifluoromethyl-1,3,5-triazino[1,2-a]benz 
imidazol-4(3H)-one 
1,2-Dihydro-7-ethoxy-2,2,3-trimethyl-1,3,5-triazino 
[1,2-a]benzimidazol-4(3H)-one 
1,2p-Dihydro-2,2,3,8-tetramethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-on 
2,2-Bis(trifluoromethyl)-1,2-dihydro-3-methyl-1,3,5-triazino[1,2-a]benzimid 
azol-4(3H)-one 
1,2-Dihydro-2,3-dimethyl-2-trifluoromethyl-1,3,5-tri 
azino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-2,2-dimethyl-3-trifluoromethyl-1,3,5-tri 
azino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-2,3-dimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
2,10-Dihydro-10-[(trifluoromethyl)sulfonyl]-2,2,3-trimethyl-1,3,5-triazino[ 
1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-2-ethyl-2-methyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
4-Oxo-2,3,4,10-tetrahydro-N,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol 
e-10-carboxamide 
1,2-Dihydro-2-propyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-2-isopropyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-3-propyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
N,3-Dipropyl-4-oxo-2,3,4,10-tetrahydro-1,3,5-triazin 
o[1,2-a]benzimidazole-10-carboxamide 
1,2-Dihydro-2,7-dimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-2,2,8-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-2,2,7,8-tetramethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-3-ethyl-2-methyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
3-Cyclopropyl-1,2-dihydro-2-methyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)- 
one 
1,2-Dihydro-2-methyl-2-vinyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
1,2-Dihydro-2-(2-propenyl)-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
2-Acetyl-1,2-dihydro-2,3-dimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-o 
ne 
1,2-Dihydro-2,3-dimethyl-2-(2-oxopropyl)-1,3,5-triazino[1,2-a]benzimidazol- 
4(3H)-one 
1,2-Dihydro-2-methoxymethyl-2-methyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H 
)-one

Examples illustrating the preparation of the compounds of the instant 
invention are contained in the copending application of C. E. Ward and R. 
E. Berthold, Ser. No. 108,284, filed concurrently herewith, assigned to a 
common assignee, and are repeated herein for purpose of convenience. 
In Example 1, the procedures described are representative of those used to 
prepare benzimidazotetrahydro-s-triazines and their 10-N substituted 
derivatives. At the end of the Examples is Table II which indicates the 
R.sup.1 -R.sup.5 and X values of each Example. 
EXAMPLE 1 
4-Oxo-2,3,4,10-tetrahydro-N,2,2,3-tetramethyl-1,3,5-triazino[1,2-a]benzimid 
azole-10-carboxamide (1A) and 
1,2-Dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one(1B 
) 
A 1-liter, round bottomed flask containing a magnetic stirrer bar was 
charged with 16 g (0.12 mole) of 2-aminobenzimidazole, 500 ml of acetone 
and 16 g of 3 A molecular sieves. The flask was fitted with a reflux 
condenser bearing a CaSO.sub.4 -drying tube after which the reaction 
mixture was stirred and heated at reflux. An additional 8 g of sieves were 
added on the second and fifth days of heating. Aliquots of the reaction 
mixture were withdrawn at 24 hour intervals, filtered, concentrated in 
vacuo and examined by NMR spectroscopy. After seven days the reaction was 
58% complete. The reaction mixture was cooled to room temperature and 
methyl isocyanate (13.7 g, 0.24 mole) was added rapidly via syringe. The 
resulting mixture was stirred overnight at room temperature after which 
time it was concentrated under reduced pressure to afford a brittle solid. 
The solid was broken up, slurried in hexane and transferred into a Soxhlet 
extraction thimble. The thimble was placed in an extractor fitted to a 
500-ml, round-bottomed flask containing a magnetic stirring bar and 400 ml 
of hexane. The material in the thimble was extracted until TLC (silica, 
80:2:1, CHCl.sub.3 :MeOH:NH.sub.4 OH) showed none of the desired products 
remained (from 2-6 da.). The solids which had precipitated in the 
extraction pot were collected with suction and the resulting filtrate was 
concentrated to provide an additional small amount of material. The 
combined solids consisted of 14.9 g of a mixture of 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
and its 10-N-methylcarbamoyl precursor 
4-oxo-2,3,4,10-tetrahydro-N,2,2,3-tetramethyl-1,3,5-triazino[1,2-a]benzimi 
dazole-10-carboxamide (.gtoreq.0.052 mole of tricyclic products; 
.gtoreq.43% yield). 
The mixture was charged to a 500 ml, round-bottom flask containing a 
magnetic stirring bar. THF (300 ml) was added followed by 30 ml of 10% 
aqueous sodium hydroxide. The resulting heterogeneous mixture was stirred 
at room temperature for 6.5 hr. after which time TLC showed that only a 
trace of the 10-N-methylcarbamoyl material remained. The reaction mixture 
was transferred to a separatory funnel and washed with brine (3.times.). 
The organic phase was dried over potassium carbonate and concentrated 
under reduced pressure to afford 11.6 g of crude product 1B as a brown 
solid (42% yield based on 2-aminobenzimidazole). This material was 
recrystallized from acetone to yield 6.9 g of pure material (1B). An 
analytical sample prepared as described above sintered at 206.degree. and 
had mp 209.degree. C. (dec). 
Anal. Calcd. for C.sub.12 H.sub.14 N.sub.4 O: C, 62.59; H, 6.13; N, 24.33. 
Found: C, 62,47; H, 6.16; N, 24.24. 
Spectral data: nmr (.delta., CDCl.sub.3) 1.73 (S, 6H, gem. methyls), 3.12 
(S, 3H, N--CH.sub.3), 6.96-7.40 (m, 3H, aromatic H), 7.83-8.16 (m, 1H, C-6 
aromatic H); ir (.nu..sub.max.sup.CHCl.sbsp.3) 31-3200 (broad, NH str.), 
1710 (C.dbd.O str.), 1660 (C.dbd.N str.), 1620, 1600, 1500, 1460, 1420, 
1380, 1310, 1290, 1230, 1170, 1140, 1100, 1050, 890 cm.sup.-1 ; uv 
(.lambda..sub.max.sup.EtOH) 282 nm (.epsilon. 7600), 287 nm (.epsilon. 
7830). 
EXAMPLE 2 
1,2-Dihydro-2,2-dimethyl-3-ethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-on 
e 
The title compound was prepared from 2-aminobenzimidazole, acetone and 
ethyl isocyanate by the procedure described in the first paragraph of 
Example 1. In this preparation, a 10-N-methylcarbamoyl derivative was not 
isolated and the subject compound was recovered from the Soxhlet 
extraction and recrystallized from acetone to give a solid, mp above 
300.degree. C. (dec). The confirmatory elemental analysis is shown in 
Table III. 
EXAMPLE 3 
2,2-Dimethyl-N,3-dipropyl-4-oxo-2,3,4,10-tetrahydro-1,3,5-triazino[1,2-a]be 
nzimidazole-10-carboxamide 
The subject compound was prepared by reaction of 2-aminobenzimidazole, 
acetone and propyl isocyanate with workup all essentially as described in 
the first paragraph of Example 1. The product was purified by column 
chromatography on silica, eluting with chloroform, giving, on evaporation, 
white crystals, mp 72.degree.-74.degree. C. The confirmatory elemental 
analysis is shown in Table III. 
EXAMPLE 4 
1,2-Dihydro-2,2-dimethyl-3-propyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-o 
ne 
The title compound was prepared by hydrolysis of the precursor compound of 
Example 3 in the presence of 10% aqueous sodium hydroxide and THF 
employing the method of paragraph 2, Example 1. The product was 
crystallized from acetone to give colorless prisms, mp 170.degree. C. 
(dec). The confirmatory elemental analysis is shown in Table III. 
EXAMPLE 5 
3-Butyl-1,2-dihydro-2,2-dimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-on 
e 
The title compound was prepared from 2-aminobenzimidazole, acetone, and 
n-butyl isocyanate, conducting the initial condensation and subsequent 
base hydrolysis of the intermediate 10-N-butylcarbamoyl precursor as 
described in Example 1. The solid product had mp 142.degree.-149.degree. 
C. (dec.). The confirmatory elemental analysis is shown in Table III. 
EXAMPLE 6 
1,2-Dihydro-2,2-dimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
A mixture of 16 g (0.12 mole) of 2-aminobenzimidazole, 100 ml of acetone 
and 16 g of 3 A molecular sieves was stirred and heated under reflux, 
adding 8 g of additional sieves after 24 hours. Refluxing was continued 
for a total period of 3 days, after which the mixture was allowed to cool 
and a solution of 4.77 g (0.06 mole) of N-chloroformamide (1) in .about.25 
ml. of acetone added dropwise with stirring. The mixture was warmed to the 
reflux point several times and the rate of N-chloroformamide addition 
adjusted to keep the temperature just below the reflux point. An 
additional 50 ml of acetone were added to facilitate stirring of the 
thickening reaction mixture. Upon completion of the feed, the reaction 
flask was fitted with a drying tube and the mixture stirred for 3 days at 
room temperature. The reaction mixture was then evaporated under reduced 
pressure to give 9.3 g of a tan solid. The latter was extracted with 
boiling acetone to separate an insoluble fraction and the acetone solution 
evaporated to give the crude solid product. The latter material was 
chromatographed on silica, eluting with CHCl.sub.3 /CH.sub.3 OH (80:5). 
Fractions 3 through 8 were combined and evaporated to give 3.9 g of 
product, mp 178.degree.-180.degree. C. (dec). elemental analysis is shown 
in Table III. 
EXAMPLE 6 
1,2-Dihydro-2,2-dimethyl-1,3,5-triazino[1,2-a]-benzimidazol-4(3H)-one 
A mixture of 16 g (0.12 mole) of 2-aminobenzimidazole, 100 ml of acetone 
and 16 g of 3 A molecular sieves was stirred and heated under reflux, 
adding 8 g of additional sieves after 24 hours. Refluxing was continued 
for a total period of 3 days, after which the mixture was allowed to cool 
and a solution of 4.77 g (0.06 mole) of N-chloroformamide (1) in .about.25 
ml. of acetone added dropwise with stirring. The mixture was warmed to the 
reflux point several times and the rate of N-chloroformamide addition 
adjusted to keep the temperature just below the reflux point. An 
additional 50 ml of acetone were added to facilitate stirring of the 
thickening reaction mixture. Upon completion of the feed, the reaction 
flask was fitted with a drying tube and the mixture stirred for 3 days at 
room temperature. The reaction mixture was then evaporated under reduced 
pressure to give 9.3 g of a tan solid. The latter was extracted with 
boiling acetone to separate an insoluble fraction and the acetone solution 
evaporated to give the crude solid product. The latter material was 
chromatographed on silica, eluting with CHCl.sub.3 /CH.sub.3 OH (80:5). 
Fractions 3 through 8 were combined and evaporated to give 3.9 g of 
product, mp 178.degree.-180.degree. C. (dec). mp 113.degree.-119.degree. 
C. (dec.). The confirmatory elemental analysis is shown in Table III. 
EXAMPLE 9 
1,2-Dihydro-2,3-dimethyl-2-ethyl-1,3,5-triazino[1,2-a]-benzimidazol-4(3H)-o 
ne 
The 10-N-methylcarbamoyl precursor prepared in Example 8 was hydrolyzed in 
the presence of 10% aqueous sodium hydroxide and THF according to the 
procedure of paragraph 2, Example 1. The product was obtained as crystals 
from acetone, mp 202.degree. C. (dec). The confirmatory elemental analysis 
is shown in Table III. 
EXAMPLE 10 
3-Butyl-4-oxo-2,3,4,10-tetrahydro-N,2,2-trimethyl-1,3,5-triazino[1,2-a]benz 
imidazole-10-carboxamide by carbamoylation of the parent heterocycle 
3-Butyl-1,2-dihydro-2,2-dimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-on 
e (2.5 g, 0.0092 mole) from Example 5 was suspended in a solution of 
triethylamine (0.5 ml) in 50 ml of acetone. The resulting mixture was 
stirred with a magnetic stirring bar, and 0.54 ml (0.0092 mole) of methyl 
isocyanate added, in one portion, by a syringe. The resulting mixture was 
stirred at room temperature, becoming a yellow solution after about 10 
minutes, and stirring was continued overnight. Solvent was removed from 
the mixture under reduced pressure and the resulting solid chromatographed 
on a silica column giving 1.8 g of title compound, mp 
124.degree.-129.degree. C. 
Anal. Calcd. for C.sub.17 H.sub.23 N.sub.5 O.sub.2 : C, 61.99; H, 7.04; N, 
21.26. Found: C, 62.11; H, 7.04; N, 21.16. 
Spectral data: nmr (.delta., CDCl.sub.3) 0.70-1.13 (m, 3H, butyl CH.sub.3), 
1.13-1.83 (m, 10H, CH.sub.3 --C--CH.sub.3 and C--CH.sub.2 CH.sub.2 --C), 
2.98 (d, 3H, J=4H.sub.z, N--CH.sub.3), 3.13-3.67 (m, 2H, N--CH.sub.2 --), 
6.97-7.33 (m, 2H, aromatic H), 7.77-8.10 (m, 1H, aromatic H), 8.10-8.43 
(m, 1H, aromatic), 9.03-9.55 (broad, 1H, NH); ir 
(.nu..sub.max.sup.CHCl.sbsp.3) 3225, 2960, 2875, 1710, 1660, 1470, 1390, 
1370, 1310, 1290, 1190, 1160, 1040, 1020, 970, 930 cm.sup.-1. 
EXAMPLE 11 
N-Ethyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benz 
imidazole-10-carboxamide 
The title compound was prepared by reaction of 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
(see Example 1 (B)) with ethyl isocyanate according to the general 
procedure of Example 10. The product, mp 127.degree.-131.degree. C., was 
obtained as a white solid in 96% yield. The confirmatory elemental 
analysis is shown in Table III. 
EXAMPLE 12 
N-Propyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3, 
5-triazino[1,2-a]benzimidazole-10-carboxamide 
The title compound was prepared from 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
(Example 1 (B)) and n-propyl isocyanate according to the procedure of 
Example 10. The confirmatory elemental analysis for the product, mp 
85.degree.-87.degree. C., is shown in Table III. 
EXAMPLE 13 
N-Isopropyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a] 
benzimidazole-10-carboxamide 
The procedure of Example 10 was used to prepare the title compound from 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
and isopropyl isocyanate. The product crystallized as a white solid, mp 
93.degree.-96.degree. C. The confirmatory elemental analysis is shown in 
Table III. 
EXAMPLE 14 
N-Butyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benz 
imidazole-10-carboxamide 
The procedure of Example 10 was used to prepare the title compound from 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
and n-butyl isocyanate. The confirmatory elemental analysis for the 
product, mp 95.degree.-97.degree. C., is shown in Table III. 
EXAMPLE 15 
N-(4-Chlorophenyl)-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino 
[1,2-a]benzimidazole-10-carboxamide 
The procedure of Example 10 was used to prepare the title compound from 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
and 4-chlorophenyl isocyanate. The confirmatory elemental analysis for the 
product, mp 206.degree.-211.degree. C., is shown in Table III. 
EXAMPLE 16 
N-tert-Butyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a 
]benzimidazole-10-carboxamide 
The procedure of Example 10 was used to prepare the title compound from 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
and tert-butyl isocyanate. The white solid product melted at 209.degree. 
C. with decomposition. The confirmatory elemental analysis is shown in 
Table III. 
EXAMPLE 17 
10-Acetyl-2,10-dihydro-2,2,3-trimethyl-1,3,5-triazino-[1,2-a]benzimidazol-4 
(3H)-one 
A 250-ml, round-bottomed flask containing a magnetic stirring bar was 
charged with 2.45 g (0.0106 mole) of 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4-(3H)-one, 
150 ml of acetone and 1.53 ml of triethylamine. Acetyl chloride (0.86 g, 
0.0110 mole) was added rapidly via syringe to the resulting solution. The 
mixture was stirred for two hours at room temperature after which time a 
white precipitate of triethylammonium hydrochloride was visible. 
Examination of the reaction mixture by TLC (silica, 80:2:1, CHCl.sub.3 
:CH.sub.3 OH:NH.sub.4 OH) showed that only a trace of starting material 
remained. The mixture was concentrated in vacuo and the resulting solid 
was taken up in methylene chloride. The resulting solution was washed with 
water (3 times) brine, dried (MgSO.sub.4) and concentrated under reduced 
pressure to afford 1.5 g (52% yield) of a white solid which was 
analytically pure, mp 159.degree.-62.degree. C. 
Anal. Calcd. for C.sub.14 H.sub.16 N.sub.4 O.sub.2 : C, 61.75; H, 5.92; N, 
20.58. Found: C, 61.70; H, 5.71; N, 20.55. 
Spectral data: nmr (.delta., CDCl.sub.3) 1.57 (S, 6H, gem. methyls), 2.70 
(S, 3H, COCH.sub.3), 3.03 (S, 3H, N--CH.sub.3), 6.93-7.37 (m, 2H, aromatic 
H), 7.77-8.07 (m, 1H, C-6 aromatic H), 8.07-8.40 (m, 1H, C-9 aromatic H); 
ir (.nu..sub.max.sup.CHCl.sbsp.3) 3000, 1720 (C.dbd.O str.), 1600, 1480, 
1380, 1350, 1290, 1190, 1150 cm.sup.-1. 
EXAMPLE 18 
N-Cyclohexyl-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a 
]benzimidazole-10-carboxamide 
The subject compound was prepared from 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
and cyclohexyl isocyanate according to the method of Example 10. The 
confirmatory elemental analysis for the product, mp 
114.degree.-116.degree. C., is shown in Table III. 
EXAMPLE 19 
2,10-Dihydro-2,2,3,10-tetramethyl-1,3,5-triazino[1,2-a]-benzimidazol-4(3H)- 
one 
A mixture of 2.0 g (0.0087 mole) 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one, 
1.1 ml (0.0174 mole) methyl iodide, anhydrous potassium carbonate (1 gram) 
and acetone (100 ml) was heated under reflux, with stirring, overnight. 
After refluxing had continued 21 hours an additional 1 ml of methyl iodide 
was added and solids removed from the mixture by suction filtration. The 
filtrate was evaporated under reduced pressure and the resulting residue 
dissolved in ethyl acetate, washed with water, then with brine and dried 
over MgSO.sub.4, filtered and solvent stripped off to give B 1.8 g of 
crude product. Purification by high pressure liquid chromatography gave a 
solid, mp 79.degree.-82.degree. C. 
Anal. Calcd. for C.sub.13 H.sub.16 N.sub.4 O: C, 63.91; H, 6.60; N, 22.94. 
Found: C, 63.79; H, 6.55; N, 22.71. 
Spectral data: nmr (.delta., DMSO-d.sub.6)1.5(S, 6H, gem. methyls), 3.0 (S, 
3H, N--CH.sub.3), 3.25 (S, 3H, N--CH.sub.3), 6.8-7.2 (m, 3H, aromatic H), 
7.55-7.84 (m, 1H, aromatic H); ir (.nu..sub.max.sup.CHCl.sbsp.3) 2955, 
1680 (strong, C.dbd.N), 1615, 1485, 1478, 1421, 1380, 1200 cm.sup.-1. 
EXAMPLE 20 
2,10-Dihydro-10-(ethoxycarbonyl)-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzi 
midazol-4(3H)-one 
The title compound was prepared from 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
(2.35 g, 0.0102 mole), ethyl chloroformate (1.1 ml, 0.0102 mole) and 
triethylamine (1 ml, 0.0102 mole) by reaction in 150 ml of acetone solvent 
according to the general method of Example 17. The yellowish, crude 
product was chromatographed on a Waters LC 500 instrument to give 1.62 g 
of a clear oil which crystallized to a solid, mp 84.degree.-86.degree. C. 
The confirmatory elemental analysis for the product is shown in Table III. 
EXAMPLE 21 
N-(3,4-Dichlorophenyl)-4-oxo-2,3,4,10-tetrahydro-2,2,3-trimethyl-1,3,5-tria 
zino[1,2-a]benzimidazole-10-carboxamide 
The procedure of Example 10 was employed to prepare the title compound from 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one 
and 3,4-dichlorophenyl isocyanate. The confirmatory elemental analysis for 
the product, mp 198.degree.-200.degree. C., is shown in Table III. 
EXAMPLE 22 
2,10-Dihydro-10-[(2-methyl)propanoyl]-2,2,3-trimethyl-1,3,5-triazino[1,2-a] 
benzimidazol-4(3H)-one 
The general procedure of Example 17 was used to prepare the title compound 
by reaction of 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one, 
isobutyryl chloride and triethylamine in acetone solution. The product was 
isolated as a yellowish oil which crystallized to a solid, mp 
99.degree.-102.degree. C. The confirmatory elemental analysis is shown in 
Table III. 
EXAMPLE 23 
2,2-Diethyl-N,3-dimethyl-4-oxo-2,3,4,10-tetrahydro-1,3,5-triazino[1,2-a]ben 
zimidazole-10-carboxamide(23 A) and 
2,2-Diethyl-1,2-dihydro-3-methyl-1,3,5-triazino-[1,2-a]benzimidazol-4(3H)- 
one(23B) 
The title compounds were prepared by reaction of 2-aminobenzimidazole, 
diethyl ketone and methyl isocyanate, employing the procedure of the first 
paragraph of Example 1. Liquid chromatographic separation of the reaction 
products give both the 10-carboxamide (23A), mp 114.degree.-125.degree. 
C., and the decarbamoylated compound (23B), mp 215.degree. C. (dec.). The 
confirmatory elemental analyses are shown in Table III. 
EXAMPLE 24 
2,10-Dihydro-10-[(4-tolyl)sulfonyl]-2,2,3-trimethyl-1,3,5-triazino[1,2-a]be 
nzimidazol-4(3H)-one 
The general procedure of Example 17 was used to prepare the title compound 
by reaction of 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one, 
para-toluenesulfonyl chloride and triethylamine in acetone solution. After 
recrystallization from ethyl acetate, the product formed colorless prisms, 
mp 147.degree.-149.degree. C. The confirmatory elemental analytical data 
are shown in Table III. 
EXAMPLE 25 
7,8-Dichloro-1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol- 
4(3H)-one 
Reaction of 2-amino-5,6-dichlorobenzimidazole with acetone and methyl 
isocyanate according to the procedure of Example 1, first paragraph, 
provided the title compound. In this case, a 10-N-methylcarbamoyl 
derivative was not isolated from the reaction mixture. The product was 
recrystallized from acetone to give a solid, mp 220.degree. C. (dec.). The 
confirmatory elemental analysis is shown in Table III. 
EXAMPLE 26 
N,3-Dimethyl-4-oxo-2,3,4,10-tetrahydrospiro[1,3,5-triazino[1,2-a]benzimidaz 
ole-2,1'-cyclopentane]-10-carboxamide 
Employing the general procedure of Example 1, paragraph 
1,2-aminobenzimidazole (16 g, 0.012 mole), methyl isocyanate (14 ml, 0.024 
mole) and cyclopentanone (250 ml) were reacted using 250 ml of 
tetrahydrofuran as a cosolvent with the excess cyclopentanone. Workup of 
the reaction mixture by liquid chromatography using CH.sub.2 Cl.sub.2 
/CH.sub.3 OH (80/1: V/V) gave the product as a solid, mp 150.degree. C. 
(dec). The confirmatory elemental analysis is shown in Table III. 
EXAMPLE 27 
3-Methyl-4-oxo-1,2,3,4-tetrahydrospiro[1,3,5-triazino-[1,2-a]benzimidazole- 
2,1'-cyclopentane] 
The reaction product of Example 26 was hydrolyzed by 10% aqueous sodium 
hydroxide and THF to give the title compound, employing the procedure of 
Example 1, paragraph 2. The product was recrystallized from acetone to 
give a solid, mp 180.degree.-182.degree. C. The confirmatory elemental 
analysis is shown in Table III. 
EXAMPLE 28 
1,2-Dihydro-2,3-dimethyl-2-(2-methylpropyl)-1,3,5-triazino[1,2-a]benzimidaz 
ol-4(3H)-one 
2-Aminobenzimidazole, methyl isobutyl ketone and ethyl isocyanate were 
reacted as in Example 26 using an equal volume of THF as cosolvent with 
the excess ketone. Working up the reaction mixture gave a crude fraction 
of the 10-N-methylcarbamoyl derivative of the title compound which was not 
purified but hydrolyzed by the 10% NaOH-THF procedure of Example 1, 
paragraph 2. The title compound was obtained as a solid, mp 
150.degree.-157.degree. C. The confirmatory elemental analysis is shown in 
Table III. 
EXAMPLE 29 
1,2-Dihydro-2,2,3,7,8-pentamethyl-1,3,5-triazino-[1,2-a]benzimidazol-4(3H)- 
one 
2-Amino-5,6-dimethylbenzimidazole monohydrate, acetone and methyl 
isocyanate were reacted, conducting the initial condensation and 
subsequent base hydrolysis of the intermediate 10-N-methylcarbamoyl 
precursor as described in Example 1. The title compound was recovered and 
purified by liquid chromatography to give a solid, mp 211.degree. C. 
(dec.). The confirmatory elemental analysis is shown in Table III. 
EXAMPLE 30 
2,10-Dihydro-10-(methylsulfonyl)-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzi 
midazol-4(3H)-one 
The general procedure of Example 17 was employed to prepare the title 
compound by reaction of 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]benzimidazol-4(3H)-one, 
methanesulfonyl chloride and triethylamine in acetone solution. The title 
compound was isolated and purified by liquid chromatography giving a 
solid, mp 147.degree. C. (dec.). The confirmatory elemental analysis is 
shown in Table III. 
EXAMPLE 31 
1,2-Dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]-benzimidazol-4(3H)-thione 
The subject compound was prepared by reacting 2-aminobenzimidazole, acetone 
and methyl isothiocyanate by the procedure described in the first 
paragraph of Example 1, above. In this case, a 10-N methylthiocarbamoyl 
derivative was not obtained and the subject compound was recovered 
directly from the Soxhlet extraction and recrystallized from acetone to 
give crystals, mp 186.degree. C. (with decomposition). 
Anal. Calcd. for C.sub.12 H.sub.14 N.sub.4 S: C, 58.51; H, 5.73; N, 22.75; 
Found: C, 58.65; H, 5.62; N, 22.98; Spectral data: nmr (.delta., 
CDCl.sub.3) 1.75 (S, 6H, gem. methyls), 3.53 (S, 3H, N--CH.sub.3), 
6.90-7.37 (m, 3H, aromatic H), 8.60-9.00 (m, 1H, aromatic H); ir 
(.nu..sub.max.sup.CHCl.spsb.3) 2700-3300 (broad, NH), 1670 (C.dbd.N str), 
1590, 1491, 1455, 1404, 1365, 1325, 1268, 1232, 1172, 1152, 1138, 1121, 
1088, 1043, 1015, 972, 885, 752, 735 cm.sup.-1 ; .sup.13 C nmr (.delta., 
CDCl.sub.3), 27.0 (gem dimethyls), 34.0 (N--CH.sub.3), 73.0 
##STR29## 
115.5, 117, 121, 124.9 (aromatic carbons bearing H), 132.5, 142.9, 149.5 
(carbons without H), 174 (C.dbd.S). 
EXAMPLE 32 
2-Cyclopropyl-1,2-dihydro-2,3-dimethyl-1,3,5-triazino-[1,2-a]benzimidazol-4 
(3H)-one 
2-Aminobenzimidazole, cyclopropyl methyl ketone and methyl isocyanate were 
reacted as in Example 26 using THF as a cosolvent with the excess ketone. 
Working up the reaction mixture gave none of the expected 
10-N-methylcarbamoyl derivative of the title compound but, rather, the 
title compound itself, recrystallized from acetone to give a solid, mp 
200.degree. C. (dec.). The confirmatory elemental analysis is shown in 
Table III. 
EXAMPLE 33 
4-Oxo-2,3,4,10-tetrahydro-N,2,2,3-tetramethyl-1,3,5-triazino[1,2-a]benzimi 
dazole-10-carboxamide: Preparation by iminium salt procedure (illustrating 
Method II, above) 
To a stirred solution of 2 g. (0.015 mole) of 2-aminobenzimidazole in 50 ml 
of acetone was added a solution of 2.99 g (0.015 mole) of 
N-isopropylidenepyrrolidinium perchlorate.sup.(2) in acetone, in one 
portion, followed by an 8-g portion of 3A molecular sieves. The resulting 
mixture was heated under reflux with stirring for approximately 23 hours, 
allowed to cool, 1.71 g (0.03 mole) of methyl isocyanate added via 
syringe, and the mixture then stirred overnight at room temperature. The 
reaction mixture was filtered and the filtrate freed of solvent under 
reduced pressure. The resulting residue was taken up in chloroform, washed 
with water, dried (MgSO.sub.4) and vacuum stripped to give 3.4 g of a dark 
oil, identified by its proton NMR spectrum as the desired product. The 
latter was purified on a high-pressure liquid chromatograph, eluting with 
CH.sub.2 Cl.sub.2 /CH.sub.3 OH (97.6%/2.4% by volume), giving 1.25 g (33% 
yield) of 4-oxo-2,3,4,10-tetrahydro-N,2,2,3-tetramethyl-1,3,5-triazino[ 
1,2-a]benzimidazole-10-carboxamide. 
FNT (2) Prepared by the procedure of N. J. Leonard and J. V. Paukstelis as 
described in J. Org. Chem. 28, 3021 (1963). 
The above compound may be used as a herbicide or, alternatively, may be 
converted to the herbicidal 
1,2-dihydro-2,2,3-trimethyl-1,3,5-triazino[1,2-a]-benzimidazol-4(3H)-one 
as described in Example 1. 
TABLE II 
__________________________________________________________________________ 
Structural Key 
##STR30## 
Example 
R.sup.1 
R.sup.2 
R.sup.3 R.sup.4 
R.sup.5 X 
__________________________________________________________________________ 
1(A) CH.sub.3 
CH.sub.3 
CH.sub.3 H CH.sub.3 NHCO 
O 
1(B) CH.sub.3 
CH.sub.3 
CH.sub.3 H --* " 
2 C.sub.2 H.sub.5 
CH.sub.3 
CH.sub.3 H -- " 
3 n-C.sub.3 H.sub. 7 
CH.sub.3 
CH.sub.3 H n-C.sub.3 H.sub.7 NHCO 
" 
4 n-C.sub.3 H.sub.7 
CH.sub.3 
CH.sub.3 H -- " 
5 n-C.sub.4 H.sub.9 
CH.sub.3 
CH.sub.3 H -- " 
6 H CH.sub.3 
CH.sub.3 H -- " 
7 (CH.sub.3).sub.2 CH 
CH.sub.3 
CH.sub.3 H (CH.sub.3).sub.2 CHNHCO 
" 
8 CH.sub.3 
CH.sub.3 
C.sub.2 H.sub.5 
H CH.sub.3 NHCO 
" 
9 CH.sub.3 
CH.sub.3 
C.sub.2 H.sub.5 
H -- " 
10 n-C.sub.4 H.sub.9 
CH.sub.3 
CH.sub.3 H CH.sub.3 NHCO 
" 
11 CH.sub.3 
CH.sub.3 
CH.sub.3 H C.sub.2 H.sub.5 NHCO 
" 
12 CH.sub.3 
CH.sub.3 
CH.sub.3 H (CH.sub.3).sub.2 CHNHCO 
" 
13 CH.sub.3 
CH.sub.3 
CH.sub.3 H n-C.sub.3 H.sub.7 NHCO 
14 CH.sub.3 
CH.sub.3 
CH.sub.3 H n-C.sub.4 H.sub.9 NHCO 
" 
15 CH.sub.3 
CH.sub.3 
CH.sub.3 H 
##STR31## " 
16 CH.sub.3 
CH.sub.3 
CH.sub.3 H (CH.sub.3).sub.3 CNHCO 
" 
17 CH.sub.3 
CH.sub.3 
CH.sub.3 H CH.sub.3 CO " 
18 CH.sub.3 
CH.sub.3 
CH.sub.3 H 
##STR32## " 
19 CH.sub.3 
CH.sub.3 
CH.sub.3 H CH.sub.3 " 
20 CH.sub.3 
CH.sub.3 
CH.sub.3 H C.sub.2 H.sub.5 OCO 
" 
21 CH.sub.3 
CH.sub.3 
CH.sub.3 H 
##STR33## " 
22 CH.sub.3 
CH.sub.3 
CH.sub.3 H (CH.sub.3).sub.2 CHCO 
" 
23(A) 
CH.sub.3 
C.sub.2 H.sub.5 
C.sub.2 H.sub.5 
H CH.sub.3 NHCO 
" 
23(B) 
CH.sub.3 
C.sub.2 H.sub.5 
C.sub.2 H.sub.5 
H -- " 
24 CH.sub.3 
CH.sub.3 
CH.sub.3 H 
##STR34## " 
25 CH.sub.3 
CH.sub.3 
CH.sub.3 7,8-Cl.sub.2 
--* " 
26 CH.sub.3 
(CH.sub.2).sub.4 
H CH.sub.3 NHCO 
" 
27 CH.sub.3 
(CH.sub.2).sub.4 
H -- " 
28 CH.sub.3 
CH.sub.3 
CH.sub.2 CH(CH.sub.3).sub.2 
H -- " 
29 CH.sub.3 
CH.sub.3 
CH.sub.3 7,8-(CH.sub.3).sub.2 
-- " 
30 CH.sub.3 
CH.sub.3 
CH.sub.3 H CH.sub.3 SO.sub.2 
" 
31 CH.sub.3 
CH.sub.3 
CH.sub.3 H -- S 
32 CH.sub.3 
CH.sub.3 
##STR35## 
H -- O 
__________________________________________________________________________ 
*-- designates hydrogen 
TABLE III 
__________________________________________________________________________ 
Physical Properties and Elemental Analyses 
Compound Calcd. Found 
Example No. 
mp .degree.C. 
Molec. Form. 
C H N C H N 
__________________________________________________________________________ 
1B 209 dec 
C.sub.12 H.sub.14 N.sub.4 O 
62.59 
6.13 
24.33 
62.47 
6.16 
24.24 
2 &gt;300 dec 
C.sub.13 H.sub.16 N.sub.4 O 
63.91 
6.60 
22.93 
63.81 
6.74 
22.91 
3 72-74 C.sub.18 H.sub.25 N.sub.5 O.sub.2 
62.9 
7.3 
20.3 
63.09 
7.00 
20.21 
4 170 dec 
C.sub.14 H.sub.18 N.sub.4 O 
65.1 
7.0 
21.7 
65.04 
6.94 
21.72 
5 142-49 dec 
C.sub.15 H.sub.20 N.sub.4 O 
66.1 
7.4 
20.6 
64.98 
7.99 
19.66 
6 178-80 dec 
C.sub.11 H.sub.12 N.sub.4 O 
61.09 
5.60 
25.91 
61.00 
5.49 
25.38 
7 80-89 C.sub.18 H.sub.25 N.sub.5 O.sub.2 
62.9 
7.3 
20.4 
63.19 
7.41 
19.67 
8 113-19 dec 
C.sub.15 H.sub.19 N.sub.5 O.sub.2 
59.78 
6.35 
23.24 
59.38 
6.16 
23.41 
9 202 dec 
C.sub.13 H.sub.16 N.sub.4 O 
63.91 
6.60 
22.94 
63.64 
6.54 
23.08 
1A 164 dec 
C.sub.14 H.sub.17 N.sub.5 O.sub.2 
58.52 
5.97 
24.38 
58.60 
5.91 
24.04 
10 124-29 
C.sub.17 H.sub.23 N.sub.5 O.sub.2 
61.99 
7.04 
21.26 
62.11 
7.04 
21.16 
11 127-31 
C.sub.15 H.sub.19 N.sub.5 O.sub.2 
59.78 
6.35 
23.24 
59.82 
6.39 
23.43 
12 85-87 C.sub.16 H.sub.21 N.sub.5 O.sub.2 
60.93 
6.71 
22.21 
60.69 
6.85 
22.36 
13 93-96 C.sub.16 H.sub.21 N.sub.5 O.sub.2 
60.93 
6.71 
22.21 
60.67 
6.56 
22.08 
14 95-97 C.sub.17 H.sub.23 N.sub.5 O.sub.2 
61.98 
7.04 
21.26 
61.84 
7.11 
21.02 
15 206-11 dec 
C.sub.19 H.sub.18 ClN.sub.5 O.sub.2 
59.45 
4.73 
18.25 
58.86 
4.66 
17.93 
16 209 dec 
C.sub.17 H.sub.23 N.sub.5 O.sub.2 
61.98 
7.04 
21.26 
61.94 
7.02 
21.25 
17 159-62 
C.sub.14 H.sub.16 N.sub.4 O.sub.2 
61.75 
5.92 
20.58 
61.70 
5.71 
20.55 
18 114-16 
C.sub.19 H.sub.25 N.sub.5 O.sub.2 
64.20 
7.09 
19.71 
64.19 
6.86 
19.57 
19 79-82 C.sub.13 H.sub.16 N.sub.4 O 
63.91 
6.60 
22.94 
63.79 
6.55 
22.71 
29 211 dec 
C.sub.14 H.sub.18 N.sub.4 O 
65.09 
7.02 
21.69 
65.21 
6.91 
21.72 
20 84-86 C.sub.15 H.sub.18 N.sub.4 O.sub.3 
59.59 
6.00 
18.53 
59.40 
5.93 
18.90 
21 198-200 
C.sub.19 H.sub.17 Cl.sub.2 N.sub.5 O.sub.2 
54.55 
4.10 
16.74 
54.37 
4.02 
16.74 
22 99-102 
C.sub.16 H.sub.20 N.sub.4 O.sub.2 
63.98 
6.71 
18.65 
63.79 
6.67 
18.66 
.sup. 23A 
114-25 
C.sub.16 H.sub.21 N.sub.5 O.sub.2 
60.93 
6.71 
22.21 
60.81 
6.62 
21.84 
.sup. 23B 
215 dec 
C.sub.14 H.sub.18 N.sub.4 O 
65.09 
7.02 
21.69 
65.04 
6.96 
21.93 
26 150 dec 
C.sub.16 H.sub.19 N.sub.5 O.sub.2 
61.32 
6.11 
22.35 
61.28 
6.11 
22.11 
27 180-82 
C.sub.14 H.sub.16 N.sub.4 O 
65.60 
6.29 
21.86 
65.67 
6.25 
21.89 
28 150-57 
C.sub.15 H.sub.20 N.sub.4 O 
66.15 
7.40 
20.57 
65.80 
7.33 
20.38 
30 147 dec 
C.sub.13 H.sub.16 N.sub.4 O.sub.3 S 
50.63 
5.23 
18.17 
49.87 
5.16 
17.93 
31 186 dec 
C.sub.12 H.sub.14 N.sub.4 S 
58.51 
5.73 
22.75 
58.65 
5.64 
22.98 
32 200 dec 
C.sub.14 H.sub.16 N.sub.4 O 
65.62 
6.29 
21.86 
65.35 
6.21 
21.67 
25 220 dec 
C.sub.12 H.sub.12 Cl.sub.2 N.sub.4 O 
48.17 
4.04 
18.73 
48.08 
3.88 
19.13 
24 147-149 
C.sub.19 H.sub.20 N.sub.4 O.sub.3 S 
59.36 
5.24 
14.57 
59.22 
5.21 
14.53 
__________________________________________________________________________ 
The compounds utilized in the compositions of the present invention are 
particularly effective in controlling the following weed species: 
______________________________________ 
Duckweed (Lemna minor) 
Salvinia (Salvinia rotundifolia) 
Cabomba (Cabomba caroliniana) 
Milfoil (Myriophyllum heterophyllum) 
Najas (Najas flexilis) 
Parrot Feather (Myriophyllum brasiliense) 
Sago Pondweed (Potamogeton pectinatus) 
Hydrilla (Hydrilla verticillata) 
Algae 
______________________________________ 
For practical use in controlling aquatic plant life, the active compounds 
of this invention can be formulated into compositions which comprise an 
inert carrier or a diluent and a toxic amount of the compound. Such 
compositions, which can also be called formulations, enable the active 
compound to be applied conveniently to the site of the aquatic weed 
infestation in any desired quantity. These compositions can be liquids 
such as solutions or emulsifiable concentrates, or solids such as 
granules, wettable powders or pellets. 
Solutions of the active compound of this invention can usually be prepared 
by dissolving the compound in a common organic solvent such as 
dimethylformamide, acetone and dimethylsulfoxide. 
Emulsifiable concentrates comprise the active compound of this invention, a 
solvent and an emulsifier. The emulsifiers most commonly used are nonionic 
or mixtures of nonionic with anionic surface active agents. 
Solid formulations such as granules can be prepared by impregnating the 
active compound, usually dissolved in a suitable solvent, onto and into 
granulated carriers such as the attapulgites or the vermiculites usually 
of a particle size range of from about 0.3 to about 5 mm. For example, a 
typical granular formulation can be prepared by charging absorbent 
granules into a tumbler mixer and then applying a solution of the active 
compound in the form of a fine spray until the desired concentration of 
active ingredient is obtained. 
Wettable powders consist of admixtures of finely divided powders of an 
inert carrier, such as talc, clay, silica, pyrophyllite and the like and 
the active compound to which wetting agents have been added. Such 
formulations are usually prepared by grinding and blending the ingredients 
until a free flowing dust of the desired particle size is obtained. 
Pelletized formulations consist of the active compound, a solid inert 
carrier and a binding agent. Suitable binding agents are hardenable 
materials, such as vinyl chloride-vinyl acetate copolymers, hydrocarbon 
resins, alkyd resins, drying oil, resin esters, varnishes, phenolic 
resins, and any of the film forming polymeric materials commonly used in 
the paint industry. Pellets are usually prepared by mixing the active 
compound, the inert carrier and the binding agent which can be in a 
solution form, until a paste results. This paste is then extruded into 
pellets of any desired size or shape and is then hardened by evaporating 
the solvent, heat curing the polymeric material or other methods as 
required. Such pelletized formulations often have the advantage of 
releasing the active ingredient at a controlled rate resulting in better 
and longer lasting control of aquatic plants. 
The concentration of the active compound of this invention in the various 
formulations will vary greatly with the type of formulation and the 
purpose for which it is designed, but generally the formulations will 
contain from about 0.05 to about 95 percent by weight of the active 
compound of this invention. 
The compositions of this invention can be applied to the site of the 
aquatic plant life infestation in a manner recognized by the art. One 
method for control of aquatic plant life comprises contacting said plant 
life with a toxic amount of the compound of this invention or a 
composition which comprises a carrier and the active compound of this 
invention. Another method for the control of aquatic plant life comprises 
contacting the water in which said plant life grows with a toxic amount of 
the compound or composition heretofore described. Yet another method 
comprises treating the soil in which aquatic weeds grow with a described 
composition. 
The quantity of active compound required to control aquatic plant life is 
dependent on a variety of factors such as the hardiness of the particular 
plant species, method of application, depth and flow of water, density of 
phytoplankton, temperature, water hardness, pH and the like. Generally, a 
rate of from about 0.05 to about 50 lb. of active compound per acre or, a 
concentration of about 0.1 to about 100 ppm in the water in which the 
weeds are growing can be required for good control of aquatic weeds. For 
example, to control submerged plants in static water a concentration of 
only about 5 ppm or less can be sufficient, however, to control the same 
plants in rapidly moving water, a concentration of up to 100 ppm may be 
required. 
The effectiveness of the compound of the present invention as aquatic 
herbicides was demonstrated by experiments wherein a wide variety of 
compounds of the invention were applied to aquatic weeds in an active 
state of growth according to the following procedure: 
To each of several large glass jars are added 3 liters of water. A solution 
prepared by dissolving 15 mg. of each test compound in acetone is then 
added to each jar to provide a concentration of 5 parts per million. When 
various concentrations of the test compound are desired, 30 mg. of the 
test compound are dissolved in 10 milliliters of acetone. This stock 
solution of each chemical to be tested as an aquatic herbicide is prepared 
in such a manner that 1 (one) milliliter of stock solution, when added to 
three (3) liters of water, will give a concentration of 1 ppm (3 mg.) 
active ingredient. Similarly, a 2 ppm concentration would require 2 
milliliters of stock solution, 4 ppm-4 milliliters, etc. 
A sample of various aquatic weeds, as specified in the table are placed in 
each jar. The jars and their contents are maintained at about 74.degree. 
F. Three weeks later the results are recorded in terms of a scale ranging 
from 0 to 10, 0 representing no injury and 10 representing complete kill. 
The results are indicated in Table IV. 
TABLE IV 
______________________________________ 
Relative Aquatic Activity at 5 ppm, where 
0 = No Effect and 10 = Complete Kill 
Test Species 
Compound/ 
Duck- 
Example No. 
weed Salvinia Elodea 
Potamogeton 
Algae 
______________________________________ 
1A 10 10 10 3 0 
1B 10 10 10 0 10 
2 6 10 10 3 10 
3 3 10 3 0 0 
4 3 10 3 0 0 
5 0 10 3 0 0 
6 10 10 6 0 0 
7 0 8 9 6 0 
8 10 10 10 6 0 
9 10 10 10 3 0 
10 0 3 6 0 0 
11 10 10 10 0 10 
12 10 10 0 0 10 
13 10 10 10 3 10 
14 10 10 10 0 0 
15 10 10 10 3 0 
16 10 10 10 0 0 
17 10 10 0 3 0 
18 10 10 6 3 0 
19 6 10 0 3 0 
20 10 10 0 3 10 
21 10 10 10 3 10 
22 10 10 6 0 10 
.sup. 23A 
10 10 3 8 0 
.sup. 23B 
10 10 6 8 0 
26 0 10 3 0 0 
27 3 10 0 0 0 
28 3 10 6 6 0 
29 10 10 10 3 10 
30 10 10 8 8 0 
31 3 10 3 3 0 
32 6 10 10 3 0 
______________________________________ 
The above data clearly demonstrates the efficacy of the compounds of the 
invention as aquatic herbicides. Advantageously, aquatic life such as 
goldfish, minnows, turtles, snails and the like, are not appreciably 
affected by the compounds in customarily employed concentrations. As a 
matter of fact, goldfish toxicity tests conducted under conventional 
procedures indicated substantially no affect against goldfish at p.p.m. of 
0.2 and 2.0 after a period of two days.