摘要:
There is disclosed a process for the preparation of thiocarbamates having the following general formula: ##STR1## wherein: R represents alkyl C.sub.1 -C.sub.4 optionally substituted with one or more halogen atoms, alkenyl C.sub.2 -C.sub.4 optionally substituted with one or more halogen atoms, phenyl optionally substituted with one or more halogen atoms, benzyl optionally substituted with one or more halogen atoms on the phenyl ring;R.sup.1 and R.sup.2, equal or different from one another, represent alkyl C.sub.1 -C.sub.4 or cycloalkyl;consisting in reacting organic dithiocarbonates with organic carbamoyl halides, in the presence of an aqueous solution of an inorganic base and a phase transfer catalyst, at a temperature of 10.degree. to 50.degree. C. for time periods of 5 to 10 hours.The thiocarbamates obtained are used as herbicides, fungicides, etc., and in general in various fields of "fine chemicals".
摘要:
A process is disclosed for preparing N-methylcarbamate of methylthioacetaldoxime, characterized in that an aqueous suspension of methylthioacetaldoxime is additioned, in one step only, with gaseous phosgene and aqueous methylamine in the presence of an inorganic alkaline base substantially at room temperature and pressure.The product obtained, known commercially as "Methomyl", is an important active principle in the field of insecticides.
摘要:
There is disclosed an improved process for selectively preparing 2-(6'-methoxy-2'-naphthyl)-propionic acid in the active antipode (+) form by reacting 2-acetyl-6-methoxynaphthalene, in an organic solvent, with a system consisting of(a) a haloform selected from CHCl.sub.3 and CHBr.sub.3 ;(b) an aqueous solution of an inorganic base selected from NaOH and KOH; and(c) a crown-ether or hydrocarbyl salt of quaternary ammonium, or of phosphonium;and hydrogenating the 2-(6'-methoxy-2'-naphthyl)-acrylic acid thus formed to obtain 2-(6'-methoxy-2'-naphthyl)-propionic acid.
摘要:
The mono-methallyl ether of pyrocatechin of formula (I): ##STR1## is prepared by reacting pyrocatechin of formula (II): ##STR2## with a methallyl halide of formula (III): ##STR3## in a homogeneous dissolving medium, e.g., alcohols, aliphatic polyalcohols and monoethers thereof, or water, in the presence of an organic or inorganic base.The mono-methallyl ether of pyrocatechin is used as an intermediate for organic syntheses and, in particular for synthesizing the product of formula (IV); ##STR4## which is marketed under the tradename "Carbofuran" and is a compound which is the active principle in soil insecticides of different overall compositions which are available on the market.
摘要:
Process for the preparation of (2,2)-paracyclophane or derivatives thereof by the Hofmann elimination of p-methylbenzyl-trimethylammonium hydroxide or derivatives thereof, in an aqueous solution of an alkali metal hydroxide, wherein said elimination is carried out in the presence of a compound of the formula (I):Y--A--(X).sub.n (I)wherein A represents an aromatic group, Y an electron donor group, X an electron acceptor group, and n is an integer from 1 to 3.
摘要:
The present invention relates to a display book system comprising a frame which defines a viewing window and a passé-par-tout which defines a viewing compartment, in a position aligned with the window of the frame, for accommodating a subject to be displayed and which is visible through the viewing window of the frame. A book portion can be annexed thereto to form the display book system. In alternative embodiments, a display book system is modified to provide a viewing compartment formed in association with the framed picture portion (frame, passé-par-tout) to allow display of discrete objects including three dimensional objects such as figurines as well as images and pictures, opaque or translucent, which are substantially two dimensional. Illumination capability is provided to allow lighting of the object displayed (front or back-lit) or self illumination. The frame itself can also be illuminated for, e.g., decorative motivation.
摘要:
Self-extinguishing expandable polystyrene particles containing an expanding agent, a self-extinguishing organic halogen-containing compound and a 2,4,6-triamino-1,3,5-triazine derivative.
摘要:
Alpha-formyl acids are prepared by carboxylation of aldehydes in the presence of unsubstituted or substituted alkaline phenates, and of aprotic organic solvents.
摘要:
Process for the preparation of (2,2)-paracyclophane or derivatives thereof by the Hofmann elimination of p-methylbenzyltrimethylammonium hydroxide or derivatives thereof, in an aqueous solution of an alkali metal hydroxide, wherein said elimination is carried out in the presence of a dialkylether of mono- and poly-ethylene glycols having the formula:R--O--CH.sub.2 CH.sub.2 O--.sub.n R' (I)wherein R and R', which may be the same or different, represent alkyl groups having from 1 to 5 carbon atoms, and n is an integer from 1 to 5.
摘要:
Carboxylic acids having the general formula:R--COOHwherein R is selected from the group consisting of aryl, aralkyl, aralkenyl, aralkynyl, heteroaryl, heteroarylalkyl, heteroarylalkenyl, heteroarylalkynyl, alkyl, alkenyl and alkynyl, optionally substituted by inert or non-reactive substituents under the reaction conditions, are obtained by oxidation of the corresponding aldehydes with an alkali metal or alkaline-earth metal chlorite in the presence of hydrogen peroxide and in an aqueous-organic solvent. The resulting carboxylic acids are utilizable as intermediates for preparing fine chemicals in known ways.