Abstract: A process for making aryl-, heteroaryl-, or cycloalkyl-substituted alkyl urethanes is disclosed. The urethanes are prepared by electrophilic carbamylation of aromatic compounds with alkylene bis(carbamic acid esters) or the equivalent in the presence of an acidic catalyst and a polar aprotic solvent. The alkyl urethanes may be cracked to give the corresponding substituted alkyl isocyanates.

Abstract: A circulation process for the production of (cyclo)aliphatic diisocyanates, in which the biscarbamate is produced from diamines, by-products from the thermal cracking, urea, and alcohol in the presence of N-unsubstituted carbamates and dialkyl carbonates, and with separation of NH.sub.3 ; the subsequent cracking of the biscarbamate is carried out in the liquid phase without solvent; the diisocyanate and alcohol are condensed; the diisocyanate is subjected to a purifying distillation; and a portion of the cracking reaction mixture is discharged with the by-products formed and recycled to the biscarbamate production step after prior reaction with the crude alcohol formed, effectively utilizes the by-products formed in the cracking step and is an industrially practical and economical process.

Abstract: The present invention relates to a process for the preparation of a polyisocyanate comprising(a) thermally decomposing in a tube reactor a solution of an N-substituted carbamic acid ester corresponding to said polyisocyanate in a solvent used as decompositoin medium, wherein said solvent (i) is capable of dissolving the carbamic acid ester, (ii) is stable at the decomposition temperature and chemically inert towards the carbamic acid esters and the polyisocyanate product, (iii) can be distilled without decomposing under the conditions of decomposition of carbamic acid estes, and (iv) has at least one miscibility gap with an extracting agent used according to the extraction step (c), said solutions being carried along the internal wall of reactor;(b) separating the gaseous materials formed in the tube reactor by fractional condensation into a fraction I comprised mainly of the alcohol by-product and a fraction II comprised mainly of polyisocyanates, isocyanatourethanes, unreacted carbamic acid ester, and the s

Abstract: The invention provides an improved method for obtaining optically active amines, carbamates, and isocyanates by thermal fragmentation of optically active ureas through refluxing the ureas in C.sub.3 -C.sub.7 alcohol solution with or without catalytic amounts of alkali metal.

Abstract: Disclosed is a peroxide monomer having the formula;CH.sub.2 .dbd.CR--A--OO--B (I)wherein R represents a hydrogen atom or an alkyl having 1 to 5 carbon atoms, A represents --NH--CO--, --CO--NH--CO--, or --CO--O--CH.sub.2 CH.sub.2 --NH--CO--, and B represents a moiety which has excluded the group (--OOH) from a hydroperoxide and a preparation thereof. The present invention also provides a polymer whose a main chain composed of carbon-carbon bonds is bonded with a pendant peroxide group represented by the formula;--A--OO--B (II)wherein A and B is the same as mentioned above, the content of the pendant peroxide group being 0.1 to 99.9% by weight and a molecular weight of said polymer being 1,000 to 100,000; and a preparation thereof.

Abstract: A process is disclosed for the preparation of aralkyl mono- and diurethanes or ureas by carbamylmethylation, or acid-catalyzed addition at a temperature of 40.degree. C. to about 100.degree. C. of formaldehyde and esters of carbamic acid to aromatic hydrocarbons. Aralkyl carbamates and ureas formed by this process can be cracked directly to produce aralkyl diisocyanates, or hydrogenated and then cracked to produce aliphatic diisocyanates, or reacted directly with polyols to produce polyurethanes by functioning as blocked isocyanates.

Abstract: Isophorone diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate (IPDI) is prepared by liquid phase thermolysis of the corresponding bis-carbamic acid ester into the corresponding isocyanate and alcohol, respectively, in the presence of a highly selective metal oxide catalyst (SnO.sub.2 and/or CuO). Typically, the cracking reaction is carried out at a temperature from 225.degree. to 350.degree. C., at a pressure of from 20 to 50 mm Hg. These catalysts give high IPDI yields with high conversions of the carbamic acid esters.

Abstract: A process is disclosed whereby mono- and diurethane cyclohexyl derivatives are obtained corresponding to the Lewis acid-catalyzed addition reaction of dipentene and methyl carbamate at a temperature of from about 40.degree. to about 150.degree.C. The mono- and diurethane cyclohexyl derivatives are pyrolytically converted to other corresponding mono- and diisocyanate cyclohexyl derivatives. Novel vinyl unsaturated monoisocyanate cyclohexyl derivatives useful as reactants for polyfunctional compounds to produce cured compositions are disclosed.

Abstract: This invention relates to novel 2-(alkoxymethyl) pentane-1,5-diisocyanates, 2-(alkoxymethyl)-pentane-1,5-diurethanes, and 2-(alkoxymethyl)-pentane 1,5-dicarbamic acid chlorides having the structure: ##STR1## in which R is a straight chain or branched C.sub.1 -C.sub.20 -alkyl radical, a straight chain or branched C.sub.2 -C.sub.20 -alkenyl radical, a straight chain or branched C.sub.3 -C.sub.20 -oxaalkyl radical, an optionally substituted C.sub.5 -C.sub.12 -cycloalkyl radical, or an optionally substituted C.sub.7 -C.sub.20 -aralkyl radical and X is a --NCO--, --NH--CO.sub.2 R.sup.1 --, --NHCO.sub.2 R.sup.2 -- OR - NHCOCl-group whereby R.sup.1 and R.sup.2 can be the same or different and are a straight chain or branched C.sub.1 -C.sub.20 -alkyl radical or a C.sub.5 -C.sub.12 cycloalkyl radical, as well as a process for their preparation.

Abstract: N-monosubstituted carbamic acid esters are thermally split on a continuous basis in a tube reactor. The carbamic acid ester which is flowed down or passed over the inner wall of a tube reactor is thermally split at a temperature of from 150.degree. to 450.degree. C. and under a pressure of from 0.001 to 20 bar into at least two fractions. One fraction is predominantly isocyanate and a second fraction is predominantly hydroxyl compound. These fractions may be separated by removing one as a gaseous fraction formed under the splitting conditions from the head of the reactor and collecting the second fraction as a liquid which accumulates at the base of the reactor. If both fractions are gaseous under the splitting conditions, they are both removed from the head of the reactor and subsequently separated by fractionating columns for example. This process is particularly advantageous in that isocyanate and hydroxyl fractions are obtained in high yield without using a solvent.

Abstract: Process for the production of N-methylcarbamates: ##STR1## (wherein RO- is the radical of a substituted phenol or of a naphthol), wherein:in a first reaction step methylamine and diphenyl carbonate are reacted with each other, operating in the liquid phase and as a continuous process, in order to form phenol and phenyl-N-methylurethane;in a second reaction step phenyl-N-methylurethane, within the related reaction mixture outcoming from the first step, is thermally continuously decomposed, to yield a gaseous stream containing methyl isocyanate, from which the components different than methyl isocyanate are condensed off;in a third step the methyl isocyanate stream, outcoming from the second step, after an optional preliminary condensation, is continuously fed and contacted with a solution of a substituted phenol or of a naphthol in an inert organic solvent, containing a basic catalyst, to form N-methylcarbamate (I);N-methylcarbamate (I) is finally recovered from the reaction mixture outcoming from the third st