Herbicidal compound, herbicidal composition containing the same and method of use thereof |
| OF THE INVENTION The compound of formula (I) of this invention which is useful in a herbicidal (... |
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2-(5-Phenyl-1,3,4-thiadiazol-2-yl)benzoic acid |
| We claim: 1. 2-(5-Phenyl-1,3,4-thiadiazol-2-yl)benzoic acid.
Description:
This ... |
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Dichloroacetylimino herbicide antagonists as plant protection agents |
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Hexahydroisoindole derivatives, and their production and use |
| I claim: 1. A compound represented by the formula ##STR8## wherein R is halogen. 2. A compound as ... |
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Selectively herbicidal N-(5-substituted-2-thiadiazolyl)-thiocarboxamides |
| I claim: 1. The selectively herbicidal composition which comprises an effective amount of a ... |
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Herbicidal mixed salts of magnesium |
| I claim: 1. a herbicidal composition comprising an inert carrier, as an essential active ingredient,... |
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Haloacyl and thiohaloacyl aryl-substituted oxazolidines and thiazolidines-herbicidal antidotes |
| What is claimed is: 1. A compound according to the formula ##STR11## in which R is haloalkyl ... |
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Certain 3-haloacyl-2,2,5-trimethyl-oxazolidines |
| What is claimed: 1. A compound having the formula ##SPC11## in which R is selected from the group ... |
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Amide derivatives of 1,3,4-thiadiazoles |
| What is claimed is: 1. A herbicidal composition comprising a carrier and a herbicidal amount of at ... |
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Removal of oxazole from acrylonitrile |
| OF THE INVENTION The cation exchange resin to be employed in the process may be any of a number of ... |
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Process for preparing 2-unsubstituted imidazoles
| Details |
Inventors: Yamamoto, Sanehiro; Yasuhara, Mitsuki; Matsunaga, Fujihisa; Okano, Masato; Nakamura, Mitsunori;
Assignee: Mitsui Petrochemical Industries, Ltd. (Tokyo, JP)
Primary Examiner: Lee; Mary C.
Assistant Examiner: Northington-Davis; Zinna
Attorney, Agent or Firm: Sherman and Shalloway
A process for preparing 2-unsubstituted imidazoles which comprises reacting an .alpha.-hydroxycarbonyl compound with a formamide in such amounts as to make the molar ratio of said formamide to said hydroxycarbonyl compound not more than 2 at a reaction temperature of 100.degree.-170.degree. C. in an atmosphere of ammonia gas. According to this process, 2-unsubstituted imidazoles may be obtained in very high yields. In addition, because no great excess of formamide is used in carrying out the reaction, an effect of not requiring the recovery operation incident to decomposition of formamide is obtained as well. And by removing formic acid formed as a by-product by the reaction, a reactor and separation equipment such as a distillation column are not corroded, and imidazoles of a high purity can be obtained. |
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DETAILED DESCRIPTION We claim: 1. A process for preparing 2-unsubstituted imidazoles represented by the following general formula (II) ##STR4## wherein R. sup. 1 and R. sup. 2 may be the same or different, and each represents: a hydrogen atom, an alkyl 1 to 14 carbon atoms; a cycloalkyl group having a carbon ring member of 4 to 8 carbon atoms, which may be unsubstituted or substituted by an alkyl group of 1 to 3 carbon atoms; an aryl group selected from the group consisting of phenyl, naphthyl and anthranyl, wherein said phenyl naphthyl or anthranyl may be unsubstituted or substituted by an alkyl group of 1 to 10 carbon atoms or an alkoxy group of 1 to 10 carbon atoms; or an arylalkyl group wherein said aryl moiety is selected from the group consisting of phenyl, naphthyl and anthranyl, wherein said phenyl, naphthyl or anthranyl may be unsubstituted or substituted by an alkyl group having 1 to 10 carbon atoms or an alkoxy group of 1 to 10 carbon atoms, and said alkyl moiety of said arylalkyl group has 1 to 14 carbon atoms; said process comprising: reacting an . alpha. -hydroxycarbonyl compound represented by the following formula (I) ##STR5## ps wherein R. sup. 1 and R. sup. 2 are the same as defined above, with a formamide at a reaction temperature of 100. degree. -170. degree. C. in an atmosphere of ammonia gas, wherein the molar ratio of said formamide to said . alpha. -hydroxycarbonyl compound is not more than 2. 2. A process according to claim 1, wherein said reaction temperature is 130. degree. -140. degree. C. 3. A process according to claim 1, wherein the partial pressure of said ammonia gas in the reaction atmosphere is 5-15 kgf/cm. sup. 2 G. 4. A process according to claim 1, wherein the reaction is carried out while said . beta. -hydroxycarbonyl compound in an amount to provide said specified ratio is being gradually added to the formamide charged in a reactor. 5. A process according to claim 1, wherein after said reaction of the . beta. -hydroxycarbonyl compound with the formamide, formic acid formed as a by-product by said reaction is removed from the reaction mixture
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