摘要:
A Process for preparing ketene in the presence of a fluidized bed material with a surface area of up to about 600 m2/g. The process is further defined as a process for preparing ketene from a sugar or glycolaldehyde feedstock.
摘要:
The present invention relates to a process for the preparation of dimethylketene (DMK) and then of polydimethylketene (PDMK) by polymerization of DMK. More specifically, the DMK is obtained by pyrolysis by isobutyric anhydride (IBAN), the latter decomposing under the effect of heat (pyrolysis) to give isobutyric acid (IBA) and DMK. One mole of pyrolyzed IBAN gives one mole of IBA and one mole of DMK.
摘要:
A process is disclosed for the synthesis of alkyl ketene dimers by the dehydrohalogenation of a C.sub.8 -C.sub.22 saturated or unsaturated linear fatty acid halide, comprising reacting the fatty acid chloride with a cyclic tertiary amine in a solvent that is selected from the group consisting of cycloalkanes and alkanes at a temperature of up to 75.degree., mechanically separating tertiary amine hydrochloride salts from alkyl ketene dimer dissolved in the solvent, and recovering the alkyl ketene dimer from the solvent.
摘要:
Stereoisomers having no cigarette beetle's sex pheromone activity contained in synthesized 4,6-dimethyl-7-hydroxy-nonan-3-one which is an equilibrium mixture of eight stereoisomers may be converted into stereoisomer having said sex pheromone activity by repeating column chromatographic fractionation, epimerization with an acidic or a basic catalyzer and/or racemization with a basic catalyzer in relation to said 3-one compound.
摘要:
Fluorinated carbonyl compounds are prepared by contacting a fluorinated methyl or ethyl ether containing at least one methoxylated carbon atom-containing group selected from: --CF.sub.2 OR.sup.3, .dbd.CFOR.sup.3, ##STR1## wherein R.sup.3 is CH.sub.3 or C.sub.2 H.sub.5, with a catalyst selected from:SbX.sub.5, TaX.sub.5, NbX.sub.5, AsX.sub.5, BiX.sub.5, TiX.sub.4, ZrX.sub.4, HfX.sub.4, FeX.sub.3,mixtures of SbX.sub.3 and SbX.sub.5, ZM'X'.sub.6, and mixtures of ZM'X'.sub.6 and M'X.sub.5 where X, independently, is F, Cl, Br or I, X' is F or Cl; and Z is H, NO, O.sub.2, alkali metal or NY.sub.4 where Y, independently, is H or alkyl of 1 to 6 carbon atoms, and M' is Sb or As at a temperature of -20.degree. to 200.degree. C.
摘要翻译:氟化羰基化合物通过使含有至少一个选自以下的含有甲氧基化碳原子的基团的氟化甲基或乙醚与选自以下的催化剂接触:其中R 3为CH 3或C 2 H 5,其中R 3为CH 3或C 2 H 5, TaX5,NbX5,AsX5,BiX5,TiX4,ZrX4,HfX4,FeX3,SbX3和SbX5的混合物,ZM'X'6以及ZM'X'6和M'X5的混合物,其中X独立地为F,Cl, Br或I,X'是F或Cl; Z为H,NO,O 2,碱金属或NY 4,其中Y独立地为H或1至6个碳原子的烷基,M'为Sb或As,温度为-20至200℃。
摘要:
2-Substituted isoxazolidine-3,5-diones and isoxazolidine-3-one-5-thiones exhibit herbicidal activity, controlling effectively the growth of a wide spectrum of grassy and broad-leaved plant species. The preparation and herbicidal activity of the compounds is exemplified.
摘要:
Alkylketene dimers are prepared by reacting acyl chlorides with tertiary amines in a molar ratio of from 1:1 to 1:1.6 at from 65 to 150° C. and with a residence time of from 1 to 30 minutes in the absence of solvents with thorough mixing and isolation of the alkylketene dimers.
摘要:
By subjecting an aromatic compound of the formula (I), which is an inexpensive raw material, to a vapor-phase intramolecular cyclodehydrogenation reaction, fluorenes of the formula (II) can be obtained industrially advantageously in a high yield. Fluorenes (II) are expected to be used as raw materials for heat-resistant epoxy resins, polycarbonates or polyesters. wherein R.sub.1 and R.sub.2 each represent a hydrogen atom, a methyl group or an ethyl group, or R.sub.1 and R.sub.2 represent .dbd.O at the same time; and R and R' each represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms.