摘要:
New cephalosporins of the formula: ##STR1## in which n=0 or 1, R.sub.1 is a radical of the formula: ##STR2## [in which R.sub.4 is a protective radical and R.sub.5 is hydrogen, alkyl, vinyl, cyanomethyl or a protective radical], or R.sub.1 is a protective radical and R.sub.2 is a protective radical or an enzymatically removable radical, or R.sub.1 is an acyl radical which may be substituted in various ways and R.sub.2 is a protective radical, in the 3-oxoethyl-bicyclooct-2-ene or -bicyclooct-3-ene or 3-oxoethylidene-bicyclooctane form if n=0, and in the 3-oxoethyl-bicyclooct-2-ene or 3-oxoethylidene-bicyclooctane form if n=1, are useful as intermediates for the preparation of 3-thiovinyl-cephalosporins useful as antibacterial agents.
摘要:
Chlorophenols are prepared by thermally dehydrochlorinating a corresponding chlorocyclohexanone in the presence of a catalyst having the formula: ##STR1## wherein A is phosphorus or arsenic, R.sub.1 and R.sub.2, which are identical or different, are each hydrogen, an alkyl radical having from 1 to 12 carbon atoms, a phenyl radical or a radical --NR.sub.4 R.sub.5, in which R.sub.4 and R.sub.5, which are identical or different, are each H or an alkyl radical having from about 1 to 5 carbon atoms, R.sub.3 is an alkyl radical having from 1 to 12 carbon atoms, a phenyl radical or a radical --NR.sub.4 R.sub.5, in which R.sub.4 and R.sub.5 are as defined above, and n is equal to 0 or 1.
摘要:
Phosphoric acid is produced by a wet process in a homogeneous medium from calcium phosphate ore, sulphuric acid and a continuously added aqueous solution of recycled acid.Part of the phosphate is treated in a primary reaction medium, prepared separately and differing in composition from the final medium sought. By regulating the compositions of the various reaction media, the present process advantageously increases the concentration of the phosphoric acid produced and/or enhances the quality of filtration, along with other advantages.The process can advantageously be applied for the economic treatment of low-grade, poorly reactive or unground phosphates.
摘要:
Random or regularly recurring block polyesteramides having glass transition temperatures at least as low as -30.degree. C. are prepared from (i) essentially difunctional monomers comprising at least one carboxylic acid function, or ester/amide-forming derivative thereof, at least 1 mol % of which comprising dicarboxylic acids or such derivatives thereof and having from 20 to 60 carbon atoms, with the amount of monofunctional carboxylic acids comprising said carboxyl monomers being less than about 1% by weight and the amount of carboxylic acids having in excess of two functional groups being less than about 5% by weight, and (ii) a member selected from the group consisting of dihydroxyl and diamino comonomers therefor, or aminoalcohol comonomers, or mixtures of diamino and aminoalcohol comonomers.
摘要:
The invention relates to a process for the recovery and the concentration of uranium (VI) contained in an organic phase. The organic phase is treated continuously in a contact zone with an aqueous solution containing an oxidizing-reducing agent in the reduced state, said oxidizing-reducing agent being capable of reducing U.sup.+6 to U.sup.+4 in said aqueous solution. The aqueous solution employed in the process issues in part or in its entirety from the cathodic compartment of an electrolytic separation cell, which is under a direct current potential, and the aqueous phase issuing from the contact zone feeds in part or in its entirety the anodic compartment of the electrolytic cell. The process is of particular interest when applied to the recovery and concentration of uranium contained in a wet process phosphoric acid.
摘要:
Intimate and efficient contacting of plural, physically disparate phases, e.g., a gas and a liquid, is achieved by contacting the phases cocurrently in a column. The gas phase is introduced at a velocity between its phase transition inversion point (T) and multiple critical point (M.sub.c) velocities, which velocity is sufficient to create a dispersion of the second phase, i.e., the liquid phase, in the gas and thereby establish at most the following zones, from bottom to top, in the column: a bottom zone of constant liquid concentration designated the emulsion zone, a zone of decreasing liquid concentration, and a zone of constant liquid concentration wherein the liquid exists in the form of droplets. The feed velocity of the liquid is adjusted accordingly to provide a mass liquid concentration value in the emulsion that is between the mass liquid concentration value transition inversion point and multiple critical point values.
摘要:
Water soluble polymeric flocculants are prepared by photopolymerizing olefinically unsaturated hydrophilic monomer(s), the photopolymerization recipe including a polyhydroxylated organic additive, such as gluconic acid. Such polyhydroxy compound facilitates solubilization of the resultant flocculants, without substantial decrease in the molecular weight thereof, and ensures against the by-production of water insoluble fractions.
摘要:
Novel 3-vinyl-cephalosporin derivates of the general formula ##STR1## in the bicyclooct-2-ene or bicyclooct-3-ene form, in which R.sub.1 is a protective radical or is a radical of the general formula ##STR2## in which R.sub.5 is hydrogen, alkyl, vinyl or cyanomethyl, or a protective radical, and R.sub.6 is hydrogen or a protective radical, and R.sub.2 is a protective radical or an enzymatically removable radical, or R.sub.1 is an acyl radical, which may carry various substituents, and R.sub.2 represents a protective radical, and R.sub.3 and R.sub.4, which are identical or different, represent alkyl (optionally substituted by hydroxyl, alkoxy, amino, alkylamino or dialkylamino) or phenyl, or form, together with the nitrogen atom, a saturated 5-membered or 6-membered heterocyclic ring optionally containing another hetero-atom, their E- and Z-forms and their mixtures, are useful as intermediates for the preparation of 3-thiovinyl cephalosporins useful as antibacterial agents.
摘要:
Novel cephalosporins of the general formula (I); ##STR1## in which R is alkyl, L-2-amino-2-carboxy-ethyl, phenyl, pyridyl, pyridyl-N-oxide, pyrimidin-2-yl, substituted pyridazin-3-yl, 5,6-dioxo-1,4,5,6-tetrahydro-1,2,4-triazin-3-yl substituted in the 4-position, 1,3,4-triazol-5-yl or 2-alkoxycarbonyl-1,3,4-triazol-5-yl substituted in the 1-position, 1,4-dialkyl-5,6-dioxo-1,4,5,6-tetrahydro-1,2,4-triazin-3-yl, 1-alkyl-5,6-dioxo-1,4,5,6-tetrahydro-1,2,4-triazin-3-yl, 2-alkyl-5,6-dioxo-1,2,5,6-tetrahydro-1,2,4-triazin-3-yl, triazol-5-yl, 1,3,4-thiadiazol-5-yl which is substituted or unsubstituted, 1,2,4-thiadiazol-5-yl which is substituted, 1,3,4-oxadiazol-5-yl which is substituted or unsubstituted, oxazol-2-yl which is substituted or unsubstituted or tetrazol-5-yl which is substituted or unsubstituted in the 1-position, R' is a hydrogen atom or a radical of the general formula (II); ##STR2## and R.sup.o is hydrogen, alkyl, vinyl or cyanomethyl, as well as their salts, are useful as anti-bacterial agents.