摘要:
Disclosed are preferred processes for preparing a 2-halo-5-halomethylpyridine compound. The preferred processes involve cyclocondensing a 2-halo-2-halomethyl aldehyde or ketone of the formula (II) ##STR1## to form a 2-halo-2-halomethylpyridine compound of the formula (III) ##STR2## wherein X is Cl or Br, Y is a cyano group or an aminocarbonyl group, and R, R.sup.1, R.sup.2 and R.sup.3 are, independently, H or an organic radical which does not interfere with the cyclocondensation.
摘要:
Disclosed are preferred processes for the preparation of 2-halo-nicotinic acid derivatives of formula (IV): ##STR1## by cyclocondensation of a 4-halo-4-cyanocarbonyl compound of formula (III): ##STR2## wherein X is Cl or Br; Y is a carbonyl group and R.sup.1, R.sup.2 and R.sup.3 are each, independently, H, Cl, Br or an organic radical. Further preferred aspects include the preparation of the above-noted 4-halo-4-cyanocarbonyl compound via Michael addition of a 2-halonitrile with an .alpha.,.beta.-unsaturated aldehyde or ketone, and the preparation of the 2-halonitrile by redistribution of halogen between a 2,2-dihalonitrile and a parent nitrile.
摘要:
Described are preferred processes for preparing 2-halo-5-substituted pyridine compounds. Preferred processes can be conducted in a one-step, one-pot fashion, and involve the reaction of a formamide and a halogenating agent with a nitrile such as cis-2-pentenonitrile or with a combination of reactants including an aldehyde such as n-propionaldehyde and a nitrile or an amide. Preferred processes provide for convenient and advantageous preparations of 2-chloro-5-methylpyridine, which serves as an intermediate to important insecticidal compounds.
摘要:
Described are processes for producing citrate esters in, an economic fashion. Esters are prepared by esterification of a citric acid-containing fermentation broth having been treated to remove cations and optionally other impurities, but containing sugar(s). Esters are also prepared by reacting an impure aqueous citric acid source with an alcohol to provide a heterogeneous aqueous/organic reacted mixture, wherein the organic phase contains the ester and the aqueous phase retains water-soluble impurities. A liquid phase separation is then used to separate the organic and aqueous phases, conveniently separating the impurities from the product and avoiding the energy-intensive distillation of water from the reaction medium.
摘要:
Described are preferred processes for preparing heterocycles having one or more nitrogen and/or oxygen heteroatoms, utilizing a 1,3-dihalopropene as an effective 3-carbon fragment. Preferred processes yield pyridines, quinolines, oxazoles, pyrimidines and pyrazoles, depending upon the other reactant or reactants utilized with the 1,3-dihalopropene.
摘要:
Described are unique polymerization processes for preparing linear polyvinylpyridine polymers as well as unique linear polyvinylpyridine polymer compositions. The processes involve the use of an alkylpyridine anion as an anionic polymerization catalyst and result in linear polyvinylpyridines having alkylpyridine end groups homologous to the pendant pyridines of the polymer. Processes of the invention are particularly advantageous in preparing relatively low molecular weight linear polyvinylpyridines without the need to use large amounts of catalyst to achieve the same.
摘要:
Processes for preparing pyridyl-substituted hydrazoles, dihydrothiadiazones or aminotriazinones by reaction of iminopyridines preformed in situ or otherwise with hydrazides or carbazides, or their sulfur counterparts, or with aminotriazinones.
摘要:
Imines are synthesized by the hydrogenation of pyridinecarbonitriles with amines in the presence of a rhodium-loaded catalyst. The resulting imines are stable and may be transiminated and then hydrogenated to form selected secondary amine products or may be hydrolyzed to aldehydes.Further, a very useful class of unsymmetrical secondary amines represented by the formula RCH.sub.2 NHAr (in which R is not aliphatic and Ar is aromatic and not attached to R), which has heretofore been accessible only with some difficulty, can be synthesized by processes herein disclosed utilizing the reductive intermolecular coupling of nitriles and primary aromatic amines.
摘要:
A cross-linked polymer-supported 4-(N-benzyl-N-methylamino) pyridine material and process for its preparation in high yield and having effective physical and catalytic properties. The polymer supported catalyst is characterized by the suspension copolymerization of an organic phase containing the corresponding vinyl-substituted pyridine monomer, a styrene monomer, and a suitable cross-linking agent and free radical-generating catalyst in the presence of an aqueous phase containing a cellulose ether derivative as the stabilizing agent. A purified acid salt of the vinyl-substituted pyridine monomer useful in polymerizations and stable for storage as either a solid or an aqueous solution.