- Metathetic sulfur transfer mediated by N-(2-aminophenyl)-4-methyl-thiazolin-2-thione derivatives: a route to diversely substituted S-alkylcarbamothioates
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A new route to S-alkylcarbamothioates is disclosed. In a first step, N-(2-aminophenyl)-4-methyl-thiazolin-2-thione is transformed into a mono- or disubstituted urea at nitrogen, and then in a second step, alkylated at sulfur. The resulting salts, after treatment with a base, gave S-alkylcarbamothioates in high isolated yields together with 3-methyl[1,3]thiazolo[3,2-a]benzimidazole under very mild conditions.
- Doukara, Abdallah Larbi,Mehdid, Mohammed Amine,Djafri, Ayada,Andreoli, Federico,Vanthuyne, Nicolas,Roussel, Christian
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experimental part
p. 1852 - 1858
(2010/04/04)
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- Solvent-assisted thiocarboxylation of amines and alcohols with carbon monoxide and sulfur under mild conditions
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DMSO or DMF as a solvent strongly accelerated the thiocarboxylation of amines and alcohols with carbon monoxide and sulfur. Under mild conditions (1 atm, 20°C), this thiocarboxylation of amines assisted by DMSO with carbon monoxide and sulfur has been developed into a practical and convenient synthetic method for S-alkyl thiocarbamates in good to excellent yields, including EPTC, thiobencarb, orbencarb, and molinate (herbicides). DMF also showed the similar solvent effect. NMP slightly decreased the effect for the thiocarboxylation of amines, and the yield of S-alkyl thiocarbamate was lowered in DMAc. Surprisingly, no formation of S-alkyl thiocarbamate was observed at the use of the other solvents, such as THF, hexane, toluene, AcOEt, MeCN, MeOH, and H 2O. The present solvent-assisted thiocarboxylation with carbon monoxide and sulfur could be also applied to a new synthesis of S-alkyl O-alkyl carbonothioates from alcohols under mild conditions (1 atm, 20°C) in DMF using DBU (1,8-diazabicyclo[5.4.0]undec-7-ene).
- Mizuno, Takumi,Iwai, Toshiyuki,Ishino, Yoshio
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p. 9157 - 9163
(2007/10/03)
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- Practical synthesis of S-alkyl thiocarbamate herbicides by carbonylation of amines with carbon monoxide and sulfur
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An industrial and economic carbonylation of amines with carbon monoxide and sulfur has been developed for the synthesis of S-alkyl thiocarbamate herbicides. In the presence of potassium carbonate and solvent DMSO, S-alkyl thiocarbamates, such as thiobencarb and orbencarb (herbicides) are synthesized in excellent yields from amines, carbon monoxide, sulfur, and alkyl halides under mild conditions (1atm, 20°C).
- Mizuno, Takumi,Iwai, Toshiyuki,Ito, Takatoshi
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p. 2869 - 2873
(2007/10/03)
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- Identification of a S-hexahydro-1H-azepine-1-carbonyl adduct produced by molinate on rat hemoglobin β2 and β3 chains in vivo
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Molinate is a thiocarbamate herbicide used in the rice industry for over 25 years, and regulatory reports have shown that administration of molinate results in reproductive toxicity in male rats. Previous in vitro studies indicate that molinate undergoes oxidative metabolism, forming reactive electrophilic intermediates capable of undergoing nucleophilic addition by protein nucleophiles. On the basis of in vitro studies, carbamylation of an active site serine residue in Hydrolase A has been proposed to be the mechanism responsible for the observed testicular toxicity. The experiments presented here utilize hemoglobin to characterize covalent protein modifications produced in vivo by molinate. Rats were dosed intraperitoneally with molinate as a function of exposure duration. Examination of globin from molinate-treated rats by HPLC demonstrated a new peak in the isolated samples and, when collected and analyzed using MALDI-TOF MS, revealed a 126 Da increase in mass relative to the native β3 chain. Digestion of the globin using Glu-C and analysis by MALDI-TOF MS revealed two modified peptide fragments at m/z 2743 and 4985 consistent with a 126 Da increase to peptide fragments [122-146] and [102-146] in the unmodified β2 and β3 chains of globin. Using selected reaction monitoring LC/MS/MS, S-hexahydro-1H-azepine-1-carbonyl cysteine (HHAC-Cys) was identified in the globin hydrolysates isolated from the molinate-treated rats, but not in the control samples, and the quantity of adduct exhibited a cumulative dose response. These experiments demonstrate the ability of molinate to covalently modify proteins in vivo in a dose dependent manner. For hemoglobin this modification was a carbamylation at Cys-125 similar to the modification produced by disulfiram and N,N-diethyldithiocarbamate. The ability of molinate to covalently modify cysteine residues provides a potential mechanism to account for enzyme inhibition following molinate exposure and suggests that enzymes with cysteine residues in their active site may be inhibited by molinate.
- Zimmerman, Lisa J.,Valentine, Holly S.,Amarnath, Kalyani,Valentine, William M.
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p. 209 - 217
(2007/10/03)
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- Triazolecarboxamide herbicides
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Compounds of the formula: STR1 wherein X is O or S; R and R1 are substituted or unsubstituted alkyl, alkenyl, alkynyl or cycloalkyl or R and R1 may be joined to form a heterocyclic ring; R2 is substituted or unsubstituted cycloalkyl; and n is 0, 1 or 2 are disclosed as well as their postemergence and preemergence selective herbicide use against both monocot and dicot weeds in crops such as sugarbeets, cotton, soybeans and rice.
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- Benzhydryl compounds as herbicide antidotes
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Acids, esters, amides and salts of benzhydryl compounds are antidotes for thiocarbamate and acetamide herbicides. These antidote compounds are especially effective to safen acetamide herbicides used to control grassy weeds and broadleaf weeds in rice, sorghum, corn and wheat.
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- Synergistic composition and method for selective weed control in rice
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Compositions that contain, in admixture with one another, as active ingredient, on the one hand N-[2-(2-methoxyethoxy)-phenylsulphonyl]-N'-(4,6-dimethoxy-1,3,5-triazin-2-yl)-urea of the formula STR1 and on the other hand one or two of the active ingredients of the formulae II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV and XV defined herein exhibit synergistic herbicidal action in rice.
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- Process for the preparation of carbamates, thiocarbamates and ureas
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The invention relates to a process for preparing carbamic acid derivatives of formula: STR1 in which R1 or R2 denotes a hydrogen atom or a substituted or unsubstituted, saturated or unsaturated aliphatic, cycloaliphatic or heterocyclic radical, or R1 and R2 together form a ring, and Y denotes OR, SR, STR2 groups, R being a substituted or unsubstituted, saturated or unsaturated aliphatic or cycloaliphatic radical, or a substituted or unsubstituted aromatic radical, R3 and R4 denote a hydrogen atom or an aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic radical or together form a ring, and R6 and R7 denote a saturated or unsaturated, substituted or unsubstituted aliphatic or cycloaliphatic radical, a hydrogen atom, an alkylthio radical or an alkyloxy radical. According to the process, a compound of formula STR3 is reacted with an α-halogenated derivative of formula STR4 at a temperature of -5° to 150° C. in the presence of an acceptor for hydrohalic acid. The carbamates, thiocarbamates or ureas obtained are very useful, especially as pesticides.
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- The Synthesis of Alkyl Thiocarbamates in an Ultrasonic Field
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The synthesis of alkylthiocarbamates from an alkali metal salt of thiocarbamic acid and halogenohydrocarbons in an aqueous medium has been investigated with exposure to ultrasound and without such exposure but under conditions of vigorous stirring.The intensifying effect of ultrasound on the synthesis thiocarbamates has been demonstrated.
- Galiakhmetov, R. N.,Valitov, R. B.,Kurochkin, A. K.,Margulis, M. A.
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p. 614 - 615
(2007/10/02)
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- Alkyl 1-Chloroalkyl Carbonates: Reagents for the Synthesis of Carbamates and Protection of Amino Groups
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The synthesis of 1-chloroalkyl carbonates and their reaction with various type of amines are described.This reaction is useful for the synthesis of carbamate pesticides and for the protection of various amino groups, including amino acids.
- Barcelo, Gerard,Senet, Jean-Pierre,Sennyey, Gerard,Bensoam, Jean,Loffet, Albert
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p. 627 - 632
(2007/10/02)
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- Controlled release of bioactive materials using alginate gel beads
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Alginate gel beads containing bioactive materials dispersed therein are the product and the process of this invention. These beads can be made to either float or sink in aqueous environments, and are capable of providing the controlled release of their bioactive materials when applied to terrestrial or aqueous environments.
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- Controlled release of bioactive materials using alginate gel beads
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Alginate gel beads containing bioactive materials dispersed therein are the product and the process of this invention. These beads can be made to either float or sink in aqueous environments, and are capable of providing the controlled release of their bioactive materials when applied to terrestrial or aqueous environments.
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- Herbicidal sulfonamides
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This invention relates to benzylsulfonylureas which are active pre- and post-emergence herbicides.
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- Thiocarbamate preparation utilizing quaternary ammonium salt catalysts
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Thiocarbamates are prepared by a process comprising reacting an aqueous solution of a thiocarbamate salt with an organic halide in the presence of a catalytic amount of a quaternary ammonium salt having the formula in which R4 and R5 are independently selected from the group consisting of C1 -C25 alkyl and C2 -C25 alkenyl, R6 and R7 are independently selected from the group consisting of C6 -C25 alkyl and C6 -C25 alkenyl, and Y- is an anion selected from the group consisting of chloride and bromide; and separating the thiocarbamate from the aqueous solution.
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- Process for the preparation of substituted S-alkyl thio-carbamates
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The invention relates to a new and advantageous process for the preparation of substituted S-alkyl thiocarbamates having the general formula (I), EQU1 wherein R1 stands for a C1-4 alkyl group, R2 stands for a C1-4 alkyl or cyclohexyl group, or R1 and R2 may form together a C4-6 polymethylene group, and R3 stands for a C2-3 alkyl group. In accordance with the invention the substituted O-alkyl thiocarbamates of the general formula (II), EQU2 wherein R1, R2 and R3 each have the same meanings as defined above, are subjected to isomerization by heating them at a temperature of 130° to 180°C in the presence of dimethyl sulfate or diethyl sulfate to yield the appropriate S-alkyl esters.
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- Process for preparing a thiolcarbamate
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Thiolcarbamates are prepared by reacting a secondary amine having the formula EQU1 wherein R1 and R2 are the same or different and each represent hydrogen, lower alkyl, alkoxy, alkenyl, alkoxyalkyl, cycloalkyl, hydroxyalkyl, benzyl or phenyl or R1 and R2 combined is a nitrogen containing heterocyclic ring with carbonylsulfide to form an intermediate of an amine salt of a thiolcarbamic acid having the formula EQU2 wherein R1 and R2 are defined as above, in an organic solvent having the formula SPC1 Wherein n is 0, 1 or 2 and R' is hydrogen, halogen or a lower alkyl group which solvent is sparingly soluble or insoluble in water and which dissolves the amine salt of the thiolcarbonic acid, and then reacting the intermediate with an alkyl halide having the formula wherein X represents halogen, and R3 represents hydrogen, lower alkyl or naphthyl or phenyl which can be substituted with halogen, alkyl, alkoxy, alkylthio, cyano or nitro, to yield a thiolcarbamate having the formula EQU3
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