Abstract: The subject of the invention is a new process for the preparation of alkyl thiochloroformates.The process according to the invention consists in reacting phosgene with a mercaptan in the presence of a catalyst which is a hexaalkylguanidinium chloride or the corresponding hydrochloride of general formula: ##STR1## in which R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 represent alkyl radicals containing 1 to 4 carbon atoms and in which n may take either the value 0 or the value 1.The preferred catalysts are hexamethylguanidinium chloride and its hydrochloride.The process according to the invention enables very pure alkyl thiochloroformates to be obtained with milder operating conditions and simplified purification operations.

Abstract: Vinyl chloroformates are described of formula ##STR1## in which: R.sub.1 .dbd.R.sub.2 .dbd.Cl, Br or a saturated 1-4 carbon atom alkyl or together they form a cycloaliphatic ring of 4-8 carbon atoms;R.sub.3 .dbd.H when R.sup.1 or R.sup.2 .dbd.alkyl; saturated alkyl of 1-4 carbon atoms or aryl; ##STR2## in which R.sub.4 .dbd.R.sub.5 .dbd.alkyl of 1-4 carbon atoms or R.sub.3 forms with R.sub.2 a C.sub.5 -C.sub.8 ring which may have attached oxygen atoms. The process of preparation consists of reacting phosgene with the corresponding compounds containing alpha halogen and a carbonyl group. The products are very useful to obtain vinyl carbonates and carbamates.

Abstract: The invention relates to a process for the preparation of 1-bromoethyl hydrocarbonyl carbonates, characterized in that anhydrous hydrobromic acid is reacted with a vinyl hydrocarbonyl carbonate of formula ##STR1## in which R denotes a saturated, substituted or unsubstituted C.sub.1 -C.sub.12 aliphatic radical or C.sub.5 -C.sub.24 alicyclic radical, or a substituted or unsubstituted aromatic radical, at a temperature between 10.degree. and 100.degree. C.The invention also relates to the new 1-bromoethyl hydrocarbonyl carbonates of formula: ##STR2## These carbonates are particularly sought after for introducing a carbonate group into a molecule.

Abstract: The invention relates to a new process for the preparation of carboxylic acid chlorides by phosgenation of the corresponding carboxylic acid in the presence of a catalyst.This process is characterized in that the said catalyst is chosen from the compounds represented by the formulae ##STR1## in which R.sub.1 to R.sub.6, which are identical of different, denote: aliphatic, alicyclic, araliphatic or aromatic radicals,or form, in pairs, with the nitrogen atom to which they are attached or with the N-C-N group, a 5- or 6-membered heterocyclic ring.The process applies to most carboxylic acids.The acid chlorides obtained are known and used to produce radical polymerization initiators or pesticides.

Abstract: Novel 2,2-dihalovinyl haloformates are described of general formula: ##STR1## in which: X is a chlorine or bromine atom;X.sub.1 and X.sub.2 are the same or different and are chlorine or bromine.The compounds are prepared by reaction of a 1,2,2,2-tetrahaloethyl haloformate of formula: ##STR2## in which: X.sub.1, X.sub.2 and X are as described hereinabove;X.sub.3 is chlorine or bromine and is always bromine when X.sub.1 and/or X.sub.2 is bromine andX.sub.4 is chlorine or bromine, with a metal such as zinc or magnesium in a solvent.The novel compounds are very useful for the preparation of 2,2-dihalovinyl carbonates and carbamates which may be used as insecticides or as comonomers.

Abstract: The invention relates to a new process for preparing active esters or carboxylic acids, which consists in reacting a carboxylic acid, in the presence of an agent for binding hydrohalic acid, with a carbonate of formula: ##STR1## in which R.sup.1 denotes either a radical of formula ##STR2## in which R.sup.3 and R.sup.4, which may be identical or different, are not hydrogen atoms and denote organic radicals which may be substituted or unsubstituted and saturated or unsaturated, and may be or may not be bound to a polymer, and which can be joined together to form a hetero-cyclic system with the nitrogen atom,or a substituted or unsubstituted aryl radical which may or may not be bound to a polymer,R.sup.2 denotes a hydrogen atom, an aliphatic or cycloaliphatic radical which may be substituted or unsubstituted and saturated or unsaturated, or a substituted or unsubstituted aromatic radical,and X denotes a halogen atom.This process is especially useful for the synthesis of active esters of N-protected amino acids.

Abstract: The invention relates to a process for preparing carbamic acid derivatives of formula: ##STR1## in which R.sup.1 or R.sup.2 denotes a hydrogen atom or a substituted or unsubstituted, saturated or unsaturated aliphatic, cycloaliphatic or heterocyclic radical, or R.sup.1 and R.sup.2 together form a ring, and Y denotes OR, SR, ##STR2## groups, R being a substituted or unsubstituted, saturated or unsaturated aliphatic or cycloaliphatic radical, or a substituted or unsubstituted aromatic radical, R.sup.3 and R.sup.4 denote a hydrogen atom or an aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic radical or together form a ring, and R.sup.6 and R.sup.7 denote a saturated or unsaturated, substituted or unsubstituted aliphatic or cycloaliphatic radical, a hydrogen atom, an alkylthio radical or an alkyloxy radical.According to the process, a compound of formula ##STR3## is reacted with an .alpha.-halogenated derivative of formula ##STR4## at a temperature of -5.degree. to 150.degree. C.

Abstract: The invention relates to a process for the preparation of 1-bromoethyl hydrocarbonyl carbonates, characterized in that anhydrous hydrobromic acid is reacted with a vinyl hydrocarbonyl carbonate of formula ##STR1## in which R denotes a saturated, substituted or unsubstituted C.sub.1 -C.sub.12 aliphatic radical or C.sub.5 -C.sub.24 alicyclic radical, or a substituted or unsubstituted aromatic radical, at a temperature between 10.degree. and 100.degree. C.The invention also relates to the new 1-bromoethyl hydrocarbonyl carbonates of formula: ##STR2## These carbonates are particularly sought after for introducing a carbonate group into a molecule.

Abstract: The invention relates to new .alpha.-chlorinated carbonates characterized in that their formula is: ##STR1## in which X is a fluorine, chlorine or bromine atom and R.sup.1 is different from the ##STR2## group and represents; a substituted or non-substituted, saturated or unsaturated, aliphatic, araliphatic, primary, secondary, tertiary or cycloaliphatic radical.These .alpha.-chlorinated carbonates are prepared by the action of a compound of formula R.sup.1 OH on a chloroformate of formula: ##STR3## in a solvent medium in the presence of an acid scavenger which is added after the two preceding compounds.They are used to block the amine function of amino acids. The .alpha.-chlorinated carbonate and amino acid are reacted in a solvent medium at a temperature of -5.degree. to 100.degree. C. in the presence of an acid scavenger. Blocked amines are very useful in peptide synthesis.

Abstract: A process for the preparation of fluoroformates of formula: ##STR1## in which R.sup.1 is a substituted or unsubstituted, saturated or unsaturated aliphatic, cycloaliphatic or polycyclic radical, or substituted or unsubstituted araliphatic radical or an aromatic radical, which consists of reacting a carbonate of formula: ##STR2## in which R.sup.1 has the same meaning as hereinabove and R.sup.2 is hydrogen, alkyl of 1-12 carbon atoms, cycloalkyl of 5-12 carbon atoms, saturated or unsaturated, unsubstituted or substituted by one or more halogen atoms or R.sup.2 is aryl, unsubstituted or substituted by one or more halogen atoms, with an alkali or alkaline earth fluoride, ammonium fluoride or a quaternary ammonium fluoride, of formula FNR.sup.3 R.sup.4 R.sup.5 R.sup.6, wherein R.sup.3, R.sup.4, R.sup.5, R.sup.6 are the same or different and are hydrogen, alkyl or aralkyl of 1-12 carbon atoms or a fluoride which is KHF.sub.2, NH.sub.4 HF.sub.2 or KSO.sub.2 F.