Abstract: In a process for separating liquid mixtures comprising formaldehyde, trioxane, alcohol, hemiformal formed from the formaldehyde and the alcohol, usual minor components and up to 5% by weight of water, the liquid mixture is distilled batchwise or continuously at reduced pressure, atmospheric pressure or superatmospheric pressure in suitable apparatuses which are to be connected to one another in an appropriate manner, and the trioxane is produced in very high purity. The other materials of value, formaldehyde and alcohol, present in the mixture can likewise optionally be separated off and recycled or used otherwise, while the minor components are ejected.

Abstract: Biologically-active, water soluble, 3-substituted trioxanes of the formula ##STR1## wherein R represents a COOH-- substituted aryl group, a substituted or unsubstituted heteroaryl group or an alkyl group, and C.sub.12 -(p-carboxy)benzyloxy trioxanes of formula ##STR2## wherein R represents a substituted or unsubstituted alkyl, alkenyl, aryl or heteroaryl group and methods for their use as antiparasitic agents, particularly for the treatment of malaria.

Abstract: The process serves for the preparation of trioxane from formaldehyde in the gas phase in the presence of a tungstomolybdophosphoric acid of the composition H.sub.3 PW.sub.n Mo.sub.m O.sub.40 .multidot.xH.sub.2 O (n=4-8, m=12-n; x=0-32) as catalyst.

Abstract: The invention relates to a method for separating a gaseous mixture comprising formaldehyde and trioxane, wherein at least some of the formaldehyde and the trioxane are dissolved from the mixture in a alcohol-containing liquid and the trioxane is crystallized from the solution thus obtained and is separated.

Abstract: A process for producing trioxane by contacting an aqueous formaldehyde solution comprising 67 wt. % formaldehyde, 30 wt. % water and 3 wt. % methanol with an acidic catalyst comprising a cation exchange resin containing a sulfonic acid group. The concentration of methanol, and formic acid which is generated during the reaction, are both controlled between 0.5-5.0 wt. % and the concentration of methanol in terms of wt. % is controlled so as not to exceed two times the concentration of formic acid in terms of wt. %. With this process, the amounts of by-products formed are small, and trioxane can be produced efficiently.

Abstract: This invention relates to a reactor 1 for the continuous production of linear or cyclic acetals, in particular trioxane, dioxolane, tetroxane, dimethoxymethane, diethoxymethane, diethoxyethane and dibutoxyethane. This reactor has internal adjacently arranged evaporator elements 2, which allow for flow-through of a heat transport medium, and which are at least two meters high so as to generate a thermosiphon flow. The clear cross section between the evaporator elements is 20 to 80% of the overall cross section. Using the reactor, circulation ratios of up to 250 can be achieved. Thus, the reliability and availability of a production plant is increased while the susceptibility to breakdown decreases.

Abstract: Novel biologically-active 3-substituted trioxanes of the formula ##STR1## wherein R represents a substituted alkyl or aryl group of 1-20, preferably 1-12, carbon atoms, and methods for the use of biologically-active 3-substituted trioxanes of this formula as antiparasitic agents, particularly for the treatment of malaria.

Abstract: To provide a practical and economical process for producing trioxane from an aqueous formaldehyde solution in the presence of a solid acid catalyst, which permits a stable operation for a long period of time.A process for producing trioxane from an aqueous formaldehyde solution by using a production apparatus comprising two functional steps, i.e. the first functional step of conducting mainly the removal of metallic impurities from the aqueous formaldehyde solution with a substance having an ion-exchanging function and the second functional step of conducting mainly the synthesis of trioxane from the aqueous formaldehyde solution, from which metallic impurities have been removed, with a solid acid catalyst.

Abstract: A process for separating a gaseous reaction mixture in the preparation of trioxane is described, in which a) the gaseous mixture leaving the reactor is scrubbed in countercurrent with an organic solvent whose boiling point is above 135.degree. C. in which the trioxane predominantly dissolves and which leaves the formaldehyde predominantly in the gas phase which is returned to the reactor, b) the trioxane together with residual formaldehyde is stripped from the solvent by distillation via a column, the overhead product being partially condensed in the temperature range from 62.degree. to 100.degree. C. c) some of the resulting condensate is applied to the column as reflux and some is taken off as product and d) the non-condensed portion is returned to the scrubbing step a).

Abstract: Disclosed are compounds having a straight or branched aliphatic hydrocarbon structure of formula I: ##STR1## In formula I, n is an integer from one to four and m is an integer from four to twenty. Independently, R.sub.1 and R.sub.2 are hydrogen, a straight or branched chain alkyl, alkenyl or alkynyl of up to twenty carbon atoms in length or --(CH.sub.2).sub.w R.sub.5. If R.sub.1 or R.sub.2 is --(CH.sub.2).sub.w R.sub.5, w may be an integer from one to twenty and R.sub.5 may be an hydroxyl, halo, C.sub.1-8 alkoxyl group or a substituted or unsubstituted carbocycle or heterocycle. Alternatively, R.sub.1 and R.sub.2 may jointly form a substituted or unsubstituted, saturated or unsaturated heterocycle having from four to eight carbon atoms, N being a hetero atom of the resulting heterocyle. R.sub.3 may be either hydrogen or C.sub.13. In the compounds, a total sum of carbon atoms comprising R.sub.1 or R.sub.2, (CH.sub.2).sub.n and (CH.sub.2).sub.m does not exceed forty. R.sub.

Abstract: A process for removing trioxane from a liquid mixture containing trioxane, water and formaldehyde, which includes distilling the liquid mixture in a first distillation stage at a low pressure, distilling the resulting distillate in a second distillation stage at a higher pressure and taking off trioxane as bottom product.

Abstract: A process for the trimerization of aqueous formaldehyde solution to produce trioxane in a multistage in situ catalyst reactor-extractor column containing a cationic exchange resin. The process entails countercurrent flow of formaldehyde solution and solvent across reactor and extractor stages wherein trioxane, produced from formaldehyde at the reactor stages, is subsequently separated at the extractor stages utilizing a suitable solvent.

Abstract: In a process for separating trioxane from an aqueous mixture consisting essentially of trioxane, water and formaldehyde, water is extracted from the mixture by pervaporation and the water-depleted mixture (retentate) is separated by rectification into trioxane and an azeotropic mixture of trioxane, water and formaldehyde.

Abstract: A process for the catalytic preparation of trioxane from formaldehyde in the gas phase employs a catalyst comprising vanadyl hydrogenphosphate hemihydrate which may be unactivated or activated by steam.No byproducts were obtained in the process and the space-time yield is high. Deposits in the reactor do not occur.

Abstract: In a process for the preparation of trioxane from formaldehyde in the gas phase in the presence of a catalyst, the catalyst employed is 11-molybdo-1-vanadophosphoric acid, H.sub.4 PVMo.sub.11 O.sub.40 .multidot.n H.sub.2 O (n=0-32).Advantages of this process are, inter alia, high space-time yields and the suppression of byproducts.

Abstract: A process for manufacturing a trimer of a low aliphatic aldehyde having 2-5 carbon atoms and the chlorinated 2-position is disclosed. The process comprises cyclically trimerizing said aliphatic aldehyde with chlorinated 2-position in the presence of a catalyst selected from the group consisting of metallic tin, metallic zinc, zeolite, and Lewis acids. It ensures easy separation of the catalyst from the target trimer and a high yield of the trimer. In addition, the unreacted raw material can be easily recovered.

Abstract: In the process for the preparation of pure trioxane by continuous or semicontinuous crystallization processes, if alkaline organic compounds are added no flocks appear after more than 120 hours of operation. As a result, blockage of the crystallization unit is prevented and problem-free running is made possible.

Abstract: A novel compound, a 2-chloropropionaldehyde trimer and a process of producing a 2-chloropropionaldehyde trimer by adding concentrated sulfuric acid to an organic solvent containing 2-chloropropionaldehyde and stirring the mixture at a temperature of from -5.degree. C. to 15.degree. C. to carry out the reaction.

Abstract: Novel 1,2,4-trioxanes which possess anti-malarial activity.

Abstract: A method of isolating trioxane by distillative separation at atmospheric pressure without extraction steps from an aqueous trioxane solution having a trioxane concentration which does not exceed that concentration, which has an constant boiling azeotropic mixture obtained at a simple distillation of said aqueous trioxane solution at normal pressure, includes heating the aqueous trioxane solution, which may also contain formaldehyde and acid, in an evaporator to form a trioxane and water vapor-containing steam mixture substantially of the azeotrope boiling temperature (about 92.degree. C. for a solution containing only water and trioxane); feeding an inert gas stream into either the evaporator or a partial condenser connected directly to the evaporator; leading the steam mixture in a first stage together with the inert gas stream through the partial condensing means, wherein the steam mixture together with the inert gas stream is cooled to a temperature of 58.degree. to 64.degree. C.

Abstract: Disclosed is a composition comprising 1,3,5-trioxane, and more particularly a stability-improved trioxane composition.

Abstract: The invention relates to a process for obtaining trioxane from aqueous solutions by high-pressure extraction using an extracting agent which is in the form either of a gas in the supercritical state or of a liquid gas. An intermediate separation is advantageous, especially in the former case.The trioxane can be obtained in high concentration and with a saving of energy by the process according to the invention.

Abstract: High molecular weight polyethylene glycol monoethers are cleaved to prepare lower oligomeric reaction products by contacting a mixture of the high molecular weight polyethylene glycol monoether and water with a hydrolytic cleavage catalyst such as alumina at elevated temperatures.

Abstract: Novel compositions comprising methanol and 1,3,5-trioxane, uses as slurry agents and/or fuels, and methods of synthesis of said compositions from gases containing carbon dioxide and light hydrocarbons are disclosed.

Abstract: The invention relates to a process for the continuous preparation of trioxane, optionally together with cyclic formals, from an aqueous formaldehyde solution in the presence of acidic solid-bed catalysts, the reaction taking place without simultaneous evaporation.The process according to the invention can be carried out even at high formaldehyde concentrations without appreciable paraformaldehyde deposits.

Abstract: Trioxane and other acetals are purified by contact with an alkali metal hydroxide and phase transfer catalyst followed by isolation in a purified form. This reaction provides acetals sufficiently pure for polymerization to high molecular weight.

Abstract: A method for synthesizing trioxane by heating and reacting an aqueous formaldehyde solution in the presence of a heteropolyacid. As the heteropolyacid, there is preferably used one that contains, as a coordinating element or coordinating elements, W, Mo, V or Nb alone or two or more of them.

Abstract: Trioxane and other acetals are purified by contacting with an alkali metal superoxide, then isolated in a purified form. Optionally, a phase transfer catalyst can be utilized in the purification. Recovered acetals are sufficiently pure for polymerization to high molecular weight.

Abstract: The invention provides a process for the continuous manufacture of trioxan, optionally together with cyclic formals, from aqueous formaldehyde solutions in a circulation reactor with evaporator, the vapor/liquid mixture leaving the evaporator is fed in below the liquid level of the reaction mixture. The process of the invention allows to attain especially high space/time yields.

Abstract: A process for recovering trioxane from an aqueous solution containing trioxane and triethylamine by the distillation separation process which comprises feeding an aqueous solution containing trioxane and triethylamine to the first distillation column, distilling out triethylamine, trioxane and water from the column top of the first distillation column, withdrawing an aqueous solution containing the major part of the trioxane present in the fed solution from the column bottom of the first distillation column, feeding the withdrawn solution to the second distillation column and taking out the substantially whole quantity of the trioxane fed to the second distillation column from the column top of the second distillation column.

Abstract: A method of purifying trioxane and other acetals by contacting them with an alkali metal and a phase transfer catalyst is described. Trioxane so purified is capable of being polymerized to high molecular weight.

Abstract: A method for synthesizing trioxane by heating and reacting an aqueous formaldehyde solution in the presence of a heteropolyacid. As the heteropolyacid, there is preferably used one that contains, as a coordinating element or coordinating elements, W, Mo, V or Nb alone or two or more of them.

Abstract: The invention relates to a process for the continuous manufacture of trioxan, if appropriate together with cyclic formals, from aqueous formaldehyde solutions in a circulation reactor with an evaporator, wherein the vapor/liquid mixture, before it enters the reactor, is separated into the vapor phase and the liquid phase, and subsequently the two phases are fed separately to the reactor. In particular, high space-time yields can be achieved by the process according to the invention. Moreover, equipment for carrying out this process is a subject of the invention.

Abstract: In a process for separating trioxane by a continuous distillation which comprises extracting, with benzene, the trioxane-containing distillate obtainable by heating an aqueous solution of formaldehyde, feeding the trioxane-containing benzene solution into a distillation column as a starting material, distilling out the benzene from the column top and withdrawing the trioxane from the column bottom, a process for separating trioxane which comprises retaining the concentration of trioxane X in the liquid composition at the starting material feeding plate of the distillation column (% by weight of trioxane based on the total liquid composition at the feeding plate) in the range satisfying the following relationship: ##EQU1## wherein R is reflux ratio, and .gamma. is a parameter defined by the following equation: ##EQU2## wherein q is the proportion of liquid part in the fed starting material as expressed in terms of ratio by weight and C (%) is the concentration of trioxane in the fed starting material.

Abstract: This invention relates to an aqueous process for recycling polyacetal, and moldings thereof, into formaldehyde monomer solution, said process occurring at elevated temperature and pressure and in the presence of an acid decomposition catalyst, such as sulfuric acid. The resultant formaldehyde monomer solution can be reacted to form trioxane and then be cycled into a trioxane-based polyacetal manufacturing process or, alternatively, it can be further treated and then be cycled into a formaldehyde-monomer-based polyacetal manufacturing process.