摘要:
3-Halogenoethyl- or propyl-2,2-dimethylcyclopropane carboxylic acid esters, which are intermediates in the preparation of synthetic pyrethroids, are prepared by the reaction of certain halogenopentenes or hexenes with a diazoacetic ester in the presence of a catalyst which is metallic copper or a copper (II) salt, a rhodium (II) salt of a carboxylic acid or a transition metal complex of certain chiral Schiff bases. By the use of the latter class of catalysts the yield of preferred cis IR isomer may be increased relative to the other possible isomers.
摘要:
3-(Halogenovinyl- or propenyl-)-2,2-dimethyl cyclopropane-1-carboxylic acid esters, which are precursors of, or may themselves be, pyrethroid insecticides, are prepared by the reaction of certain halogenopentadienes with an alkyl diazoacetate in the presence of a catalyst which is a transition metal complex of certain chiral Schiff bases, which catalysts tend to increase the yield of preferred cis IR isomer relative to the other possible isomers.
摘要:
Chiral Schiff bases, and transition metal complexes thereof, of formula: ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3, which may be the same ordifferent, are hydrogen, alkyl, aralkyl, aryl, alkaryl, a substituent containing a hetero atom, or two of R.sup.1, R.sup.2 and R.sup.3 together with the pyridine ring from fused system, R.sup.4 and R.sup.5 which may be the same or different, are hydrogen, lower alkyl, or, where n is 1, may with the pyridine ring to which CR.sup.4 R.sup.5 is attached form a fused system, R.sup.6 is hydrogen, alkyl, aralkyl, aryl or alkaryl, n is 0, 1 or 2 and J and K, which may be the same or different, are groups of the formulae: ##STR2## in which C* is an asymmetric carbon atom, and R.sup.7 and R.sup.8, which may be the same or different, are alkyl, aralkyl, aryl or alkaryl, or ##STR3## in which at least the ring carbon atom to which the iminyl nitrogen atom is attached is asymmetric, at least one of the carbon atoms adjacent the said ring carbon atom bears a hydroxyl group, R.sup.9 and R.sup.14, which may be the same or different, are hydrogen or lower alkyl, R.sup.10 is hydrogen, or lower alkyl, or together with R.sup.15 forms a divalent hydrocarbyl group, R.sup.11 is hydrogen, a sugar residue, or --CH.sub.2 OR.sup.15 in which R.sup.15 is hydrogen, lower alkyl or together with R.sup.10 forms a divalent hydrocarbon group, R.sup.12 is hydrogen or --CH.sub.2 OR.sup.15 in which R.sup.15 is hydrogen, or a lower alkyl, R.sup.13 is hydrogen, OR.sup.1, or a sugar residue, provided that both R.sup.12 and R.sup.13 are not hydrogen, m is 0, 1 or 2, p is 0 or 1 provided that m plus p is 0, 1, 2 or 3. The transition metal is for example copper (II), chromium (II), manganese (II), iron (II), cobalt (II), nickel (II) or palladium (II). The aforesaid complexes may be used as catalysts in the cyclopropanation of olefins by diazoacetates to form insecticide or insecticide precursors.
摘要:
Chiral Schiff bases according to the general formula: ##STR1## and transition metal complexes thereof, wherein C.sup.* is an asymmetric carbon atom, R.sup.1 and R.sup.2, which may be the same or different are alkyl, aralkyl, aryl or alkaryl, R.sup.3 is hydrogen, alkyl, aralkyl, aryl or alkaryl, R.sup.4 and R.sup.5, which may be the same or different, are hydrogen or lower alkyl or, where n is 1, may with the cyclic ring to which CR.sup.4 R.sup.5 is attached form a fused system, J is a chain of 3 or 4 atoms which may all be carbon atoms or may be a mixture of carbon atoms and one or more hetero atoms which may be the same or different, which chain with the group C K forms an aromatic system, K is nitrogen, ##STR2## or --NH--, L, each of which may be the same or different, represents a substituent attached to a carbon atom in the chain J and is hydrogen, alkyl, aralkyl, alkaryl, aryl or a substituent containing a hetero-atom; or two L's together with the cyclic ring to which they are attached form a fused system, n is 0, 1 or 2, m is the number of carbon atoms in the chain J. The transition metal is for example copper (II), chromium (II), manganese (II), iron (II), cobalt (II) nickel (II) or palladium (II). The aforesaid complexes may be used as catalysts in the cyclopropanation of olefins by diazoacetates to form insecticide or insecticide precursors.
摘要:
Process for the production of 2,5-dimethyl-1,5-hexadiene by heating isobutene with a 1,1,2-trihalo ethylene in the vapor phase in the presence of a free-radical generator. The free-radical generator is preferably a peroxide and the reaction temperature in the range 200.degree.-600.degree. C. The product may be readily isomerized to 2,5-dimethyl-2,4-hexadiene, which is useful as an insecticide intermediate.
摘要:
Chiral Schiff bases according to the general formula: ##STR1## and chiral transition metal complexes thereof, wherein at least the carbon atom of the monosaccharide to which the iminyl nitrogen atom is attached is asymmetric, and at least one of the carbon atoms adjacent the aforesaid carbon atom bears a hydroxyl group, R.sup.1 and R.sup.6 which may be the same or different, are hydrogen or lower alkyl, R.sup.2 is hydrogen, or lower alkyl or together with R.sup.10 forms a divalent hydrocarbon group, R.sup.3 is hydrogen, a sugar residue, or --CH.sub.2 OR.sup.10 in which R.sup.10 is hydrogen, lower alkyl or together with R.sup.2 forms a divalent hydrocarbon group, R.sup.4 is hydrogen or --CH.sub.2 OR.sup.10 in which R.sup.10 is hydrogen, or a lower alkyl, R.sup.5 is hydrogen, OR.sup.1 or a sugar residue, provided that both R.sup.4 and R.sup.5 are not hydrogen, R.sup.7 and R.sup.8 which may be the same or different, are hydrogen, or lower alkyl, or where p is 1, may with the cyclic ring to which CR.sup.7 R.sup.8 is attached form a fused system, R.sup.9 is hydrogen, alkyl, aralkyl, aryl or alkaryl, J is a chain of 3 or 4 atoms which with the group C A forms an aromatic system, which atoms may be carbon atoms or may be a mixture of carbon and one or more hetero atoms which may be the same or different, A is nitrogen, or ##STR2## or --NH--, L each of which may be the same or different, represents a substituent attached to a carbon atom in the chain J and is hydrogen, an alkyl group, aralkyl group, aryl, alkaryl or a substituent containing a hetero-atom; or two L's together with cyclic group to which they are attached form a fused system, m is 0 or 1, n is 0, 1 or 2, provided that n plus m is 0, 1, 2 or 3, p is 0, 1 or 2 and q is the number of carbon atoms in the chain J. The transistion metal is for example copper (II), chromium (II), manganese (II), iron (II), cobalt (II), nickel (II) or palladium (II). The aforesaid complexes may be used as catalysts in the cyclopropanation of olefins by diazoacetates to form insecticide or insecticide precursors.
摘要:
Process for the preparation of 3(2,2-dihalovinyl)-2,2-dimethyl cyclopropane carboxylic acids, especially permethrin acid ethyl ester, by reacting a diazoacetic acid ester with a 1,1-dihalo-4-methyl-1,3-pentadiene in the presence of a catalyst comprising a divalent rhodium salt of a carboxylic acid or borofluoric acid. The products have improved yields and better cis/trans isomer ratios than when the more common catalysts, e.g. copper-bronze, are used.
摘要:
Polyhalogenated hydrocarbons of general formula RR.sup.1 CH--CHX--CH.sub.2 CYZQ wherein R is hydrogen or lower alkyl, R.sup.1 is lower alkyl, X is Cl, Br or I, Y is F, Cl or Br, Z is Y or Q and Q is a group W(CF.sub.2).sub.m --in which W is hydrogen, F or Cl and m is 1 or 2, provided that X is always Br or I when at least one of Y and Z is Br, and a process for preparing these polyhalogenated hydrocarbons by reacting an alkyl-substituted butene with a polyhalogenated alkane having from 2 to 4 carbon atoms, in the presence of a catalyst.
摘要:
The invention provides compounds of formula: ##STR1## wherein R.sup.1 represents hydrogen or halogen and R.sup.2 represents C.sub.1-8 alkyl or C.sub.1-8 haloalkyl, useful as insecticides and knockdown agents. The invention also provides compositions comprising them, methods of their use in controlling insects, and processes for their preparation.
摘要:
A process for the preparation of alkyl furans which comprises reacting furan with an alkyl halide in the presence of iron (III) oxide and an iron (II) halide or iron (III) halide as catalyst.