Abstract:
Discloses indan derivatives represented by the general formula [1] ##STR1## wherein R is a lower alkoxy group, a phenoxy group, ##STR2## whereupon R 1  and R 2  are, respectively, a hydrogen atom, a lower alkyl, lower alkenyl, phenyl, or phenyl group substituted by halogen atoms, or a monopholino group. 
     The indan derivatives demonstrated satisfactory results in respect of a weeding effect and safety in practical use.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to indan derivatives, more particularly, novel indan derivatives which are excellent in a weeding activity. 
     In recent years, many herbicides have been developed and have contributed to the labor-saving of farming and the improvement of productivity. However, it is hard to say that the herbicides are satisfactory in respect of a weeding effect and safety in practical use. Thus, further improved herbicides have been desired. 
     The present inventors eagerly studied and researched for development of chemicals which are excellent in a weeding effect, to find out novel indan derivatives bearing specific substituents showing a nigher weeding effect, and arrived at the present invention. 
     SUMMARY OF THE INVENTION 
     The present invention provides indan derivatives represented by the following general formula [I]: ##STR3## wherein R is a lower alkoxy group, a phenoxy group, ##STR4## whereupon R 1  and R 2  are, respectively, a hydrogen atom, a lower alkyl, lower alkenyl, phenyl, or phenyl group substituted by halogen atoms, or R 1  and R 2  together with the nitrogen atom to which they are bonded form a morpholino group. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The indan derivatives of the present invention are represented by the following general formula [I]: ##STR5## wherein R is a lower alkoxy group, a phenoxy group ##STR6## whereupon R 1  and R 2  are, respectively, a hydrogen atom, a lower alkyl, lower alkenyl, phenyl, or phenyl group substituted by halogen atoms, or a morpholino group. 
     In the formula, the groups represented by R include, as a lower alkoxy group, a methoxy, ethoxy, propoxy, isopropoxy, butoxy, s-butoxy, isobutoxy, t-butoxy, and pentyloxy groups, and the groups represented by R 1  and R 2 , respectively, include, as a lower alkyl group, a methyl, ethyl, propyl, isopropyl, butyl, s-butyl, and isobutyl groups, and as a lower alkenyl group, an allyl and butenyl groups, and as a phenyl group substituted by halogen atoms, a chlorophenyl, dichlorophnyl, trichlorophenyl, fluorophenyl, difluorophenyl, bromophenyl, dibromophenyl, iodophenyl, bromochlorophenyl, and chlorofluorophenyl groups. 
     Among the compounds of the present invention, the compounds in Table 1, for example, are given as the particularly preferred ones. 
     
                       TABLE 1______________________________________ ##STR7##Com-                Com-pound               poundNo.    R            No.      R______________________________________1      OCH.sub.3    7        N(C.sub.2 H.sub.5).sub.22      OC.sub.3 H.sub.7.sup.iso               8        NH(CH.sub.2 CHCH.sub.2)3      OC.sub.4 H.sub.9.sup.s               9                         ##STR8##   ##STR9##    10                         ##STR10##5      NH.sub.2     11                         ##STR11##6      NHCH.sub.3   12                         ##STR12##______________________________________ 
    
     [Synthesis of Indan Derivatives] 
     The indan derivatives of the present invention could be synthesized according to the following reaction formulae (1) to (3). ##STR13## 
     The reaction (1) proceeds easily at 0 to 30° C. under a solventless condition or in a solvent, such as halogenated hydrocarbons, in the presence of an acid catalyst, such as sulfuric acid, and aluminium chloride, etc. The reaction (2) proceeds easily at 0° to 40° C. in an inert solvent, such as halogenated hydrocarbons, in the presence of a Lewis acid, such as aluminium chloride, etc. 
     Among the indan derivatives of the present invention, the esters, i.e. the derivatives in which R is a lower alkoxy group, or a phenoxy group, can be synthesized by reaction of acid chloride obtained from carboxylic acid [III] and equimolar thionyl chloride with corresponding ROH, i.e. alcohols or phenol, in the presence of a base, i.e. such as triethylamine, pyridine, etc. Among the indan derivatives of the present invention, the amides, i.e. the derivatives in which R is --N(--R 1 )--R 2 , whereupon R 1  and R 2  are the same as those already defined, or R is a morpholino group, can be synthesized by reaction of the above-described acid chloride with the corresponding amines with molar ratio of the former to the latter of 1:2 to 10 in the reaction. 
     In the below, the syntheses will be explained definitely with referring to synthesis examples. 
     Synthesis Example 1 
     Synthesis of methyl 3-(1,1-dimethyl-6-isopropyl-4-methyl-5-indanoyl)acrylate (Compound No. 1) 
     To a 100 ml flask equipped with a thermometer, a reflux condenser, a dropping funnel, and a stirrer, were added 20 ml of methylene chloride, 10.0 g (33 m mole) of 3-(1,1-dimethyl-6-isopropyl-4-methyl-5-indanoyl) acrylic acid (the compound of the formula III), and 2.5 ml (33 m mole) of thionyl chloride at room temperature, followed by reaction under reflux for 2 hrs., to obtain a methylene chloride solution of acid chloride thereform. To this was added the mixture of 10 ml of methanol and 10 ml of pyridine at -20° C, followed by being stirred for 1 hr at -20 to -10° C. The reaction mixture was poured into 100 ml of water, and was then extracted with 200 ml of ether. 
     The ether layer was washed with 0.5 N HCl and dried by sodium sulfate. Following removal of the ether, the product was subjected to vacuum distillation, to obtain 6.3 g (yield: 60%) of the objective product in the form of a yellow crystal (m.p.: 88° to 89° C.), from the fractions of b.p. 160° to 163° C./1.6 mmHg. 
     NMR spectrum (CDCl 3 ) δ1.17 (d,6H,J=7H z ) 1.25(s,6H), 1.92(t, 2H,J=7H z ), 2.04(s.3H), 2.66 (sept., 1H, J =7H z )m 2.77 (t,2H, J=7H z ), 3.78 (s,3H), 6.38 (d,1H, J=16H z ), 6.94 (s,1H), 7.22 (d, 1H, J=16H z ) 
     Synthesis Example 2 
     Synthesis of 3-(1,1-dimethyl-6-isopropyl-4-methyl-5-indanoyl)-acryl amide (Compound No. 5) 
     The reaction was performed in the same manner as those disclosed in Synthesis Example 1 except that 15 ml of 25% aqueous ammonia was added in place of 10 ml of methanol and 10 ml of pyridine. The resultant impure crystals were recrystalized from ethyl acetate - toluene, to obtain the objective product with 70% yield (yellow powder with m.p. of 235° to 237° C.). 
     NMR spectrum (CDCl  3 ) δ1.15 (d,6H, J=7.5H z ), 1.24 (s, 6H), 1.89 (t, 2H, J=7.5H z ), 2.01 (s, 3H), 2.63 (sept. ,1H, J=7H z ), 2.76 (t, 2H, J=7.5H z ), 6.52 (d, 1  H, J=17H z ), 6.94 (s, 1H), 7.06(d, 1H, J=17H z ), 7.14(s,1H), 7.84(s,1H) 
     Synthesis Examples 3 to 10 
     The compounds in Table 2 were synthesized in the same manner as those disclosed in Synthesis Example 1 or 2. 
     
                       TABLE 2______________________________________Com-pound YieldNo.   (%)     mp (°C.)                  Spectrum data______________________________________2     80      69˜71                  NMR (CDCl.sub.3)                  δ1.17(d, 6H, J=7Hz), 1.24(s, 6H),                  1.26(d, 6H, J=5Hz), 1.90(t, 2H, J=                  7Hz), 2.03(s, 3H), 2.68(m, 1H), 2.75                  (t, 2H, J=7Hz), 5.07(sept., 1H, J=7                  Hz), 6.32(d, 1H, J=16Hz), 6.94(s,                  1H), 7.20(d, 1H, J=16Hz)3     76      65˜674     90      Liquid   IR (neat, ν c=o)1740, 1660 cm.sup.-17     81      50˜52                  NMR (CDCl.sub.3)                  δ1.13(t, 6H, J=7Hz), 1.20(d, 6H, J=                  7Hz), 1.25(s, 6H), 1.91(t, 2H, J=                  7Hz), 2.07(s, 3H), 2.77(t, 2H, J=                  7Hz), 3.30(q, 2H, J=7Hz), 3.44(q, 2H,                  J=7Hz), 6.92(d, 1H, J=16Hz), 6.97                  (s, 1H), 7.17(d, 1H, J=16Hz)9     90      184˜186                  IR (KBr Disk ν c=o) 1653 cm.sup.-110    67      235˜236                  NMR (CDCl.sub.3 /DMSO-d.sub.6)                  δ1.19(d, 6H, J=8Hz), 1.25(s, 6H),                  1.91 (t, 2H, J=8Hz), 2.06(s, 3H),                  2.70(m, 1H), 2.78(t, 2H, J=8Hz), 6.74                  (d, 1H, J=16Hz), 6.97(s, 1H), 7.28                  (d, 1H, J=16Hz), 7.29(d, 1H, J=                  10Hz), 7.50(d, 2H, J=10Hz), 7.94                  (s, 1H)11    80      225˜227                  IR (KBr Disk ν c=o) 1689,                  1638 cm.sup.-112    86      149˜150                  IR (KBr Disk ν c=o) 1673,                  1637 cm.sup.-1______________________________________ 
    
     The indan derivatives relating to the present invention show a higher weeding effect on many kinds of annual broad-and narrow-leaved weeds in a paddy field or an upland field. 
     In order to employ the compounds of the present invention as a herbicide, the present compound is sprayed after being diluted to a suitable concentration or directly applied, solely, or in the form of chemicals, such as wettable powder, emulsion, fine powder, granules, or the like, into which a carrier, a surface-active agent, a dispersing agent, an adjuvant, or the like, is compounded. 
     For use, the compounds of the present invention, or chemicals containing said compounds, not only can be sprayed on crops directly, but also can mixed in soil. 
     The applied amounts differ depending on the type and the degree of objective weeds and damages, the type of crops, and the application mode. For use as an usual herbicide, however, the effective amounts are about 1 to 100 g per are. 
     Following are compounding examples for chemicals, in which the present compounds are employed as an active ingredient. In the following disclosure, &#34;percent&#34; means weight percent, and &#34;parts&#34; means weight parts. 
     Compounding Example 1 (Wettable powder) 
     The compound of the present invention, sodium salt of higher alcohol sulfate, and kaoline whose compounding ratio was 10:3:87 by percent, respectively, were mixed and grained, to produce wettable powder. 
     Compounding Example 2 (Emulsion) 
     The compound of the present invention, polyoxyethylene alkyl arylether, cyclohexanone, and dimethylformamide were dissolved uniformly in the compounding ratio of 20:10:30:40 by percent, respectively, to produce emulsion. 
     Compounding Example 3 (Granules) 
     The compound of the present invention, bentonite, and clay whose compounding ratio was 5:40:50:5 by percent, respectively, were mixed and grained uniformly. Following addition of water thereto and milling, the resultant product was formed into granules and dried, to produce granules. 
     Compounding Example 4 (Fine powder) 
     The compound of the present invention was mixed with clay, and then grained uniformly in the compounding ratio of 3 to 97 by percent, respectively, to produce fine powder. 
     Next, the weeding effect by the present compounds will be explained with referring to test examples. 
     Test Examples 1 to 10 
     Two sheets of filter papers were put in a 9 cm diameter laboratory dish with a cap, and seeds of Echinochloa crus-galli, Digitaria adscendens, Cyperus iria L., Scirpus juncoides subsp., and Amaranthus viridis, were put on the filter papers. 20 ml of liquid fertilizer and a test compound (wettable powder) was given after dilution with water, so as to be sprayed thereupon in a proportion of 100 g/10 ares as an active ingredient. After exposed to light (3,000 luxes) for 10 days at 30, the weeding effects were evaluated visually based on the standards in Table 3. 
     
                       TABLE 3______________________________________Index       Weeding effect______________________________________4.5         90% to 99%4           80% to 89%3.5         70% to 79%3           60% to 69%2.5         50% to 59%2           40% to 49%1.5         30% to 39%1           20% to 29%0.5         19% to 1%0           none______________________________________ 
    
     Results are shown in Table 4. 
     
                                           TABLE 4__________________________________________________________________________        Weeding EffectTested Compound        Echinochloa              Digitaria                    Cyperus                         Scripus Amaranthus(Compound No.)        crusgalli              adscendens                    iria L.                         juncoides subsp.                                 viridis__________________________________________________________________________1            4     4     5    4       52            3     3     4    3       53            3     2.5   4    3       44            4     4     5    4       55            5     5     5    4       57            5     3     4.5  4       4.59            2     5     4    3       310           4     3     3    3       411           4     4     5    3       412           4     4.5   5    4       5Comparative Compound*        1     0     0    0       1__________________________________________________________________________ *3-(1,1-dimethyl-6-isopropyl-4-methyl-5-indanoyl)acrylic acid represented by the formula: ##STR14##