Patent GB-613280-A (GB)
Title: Hydrazo esters
Filed: 1946-06-17
Abstract: The Specification as open to inspection under Sect. 91 comprises the manufacture of linear and cross-linked high molecular condensation products <FORM:0613280/IV(a)/1> (wherein R represents a polyvalent hydrocarbon, oxahydrocarbon or thiahydrocarbon radical or a corresponding nitro- or halogen-substituted radical, x is a small whole number greater than one and equal to the valency of R, and y represents the number of R residues in the chain), by reacting hydrazine with polychlorocarbonates containing respectively two, and three or more, chlorocarbonate groups.  This subject-matter does not appear in the Specification as accepted.ALSO:Hydrazo-esters of the general formula <FORM:0613280/IV(b)/1> (wherein R is a polyvalent and R1 a monovalent hydrocarbon, oxahydrocarbon or thiahydrocarbon radical or a corresponding nitro- or halogen-substituted radical, and x is a small whole number greater than one and equal to the valency of the R radical) are manufactured by reacting a polychlorocarbonate of the formula <FORM:0613280/IV(b)/2> with x molecular proportions of a compound H2N-NH-COOR1, preferably in the presence of a solvent (e.g. dioxane) and a basic reagent (e.g. dimethylaniline, pyridine or other tertiary amine, or an alkali or alkaline-earth metal oxide, carbonate or hydroxide).  Specified radicals, some of which are exemplified, are: R : alkylene radicals (e.g. ethylene, hexamethylene, decamethylene and 1 : 2-propylene), oxaalkylene radicals (e.g. -C2H4-O-C2H4- and -C2H4-O-C2H4-O-C2H4-), corresponding thioether radicals (e.g. -C2H4-S-C2H4-and -C2H4-S-C2H4-S-C2H4-), arylene radicals (e.g. p-phenylene and the various naphthylene radicals), divalent radicals having both aryl and aliphatic characteristics (e.g. tolylene, toluylene, xylylene, diphenylenemethane and 2 : 2-bis-(diphenylene-11 : 41)-propane), halo-, alkyl- and nitro-substitution products of any of the foregoing, and radicals having a valency greater than 2 (e.g. glyceryl, pentaerythryl and similar thia- and oxahydrocarbon radicals and corresponding alkyl-, halo- or nitro-substituted radicals); R1 : alkyl radicals (e.g. methyl, ethyl, cetyl and melissyl), aryl radicals (e.g. phenyl and naphthyl), aralkyl radicals (e.g. benzyl, phenylethyl and naphthylmethyl), cycloalkyl radicals (e.g. cyclohexyl and cyclopentyl), alkoxyalkyl radicals (e.g. 2-methoxyethyl, 2-ethoxyethyl and 2-isopropyloxy-n-propyl), thia-alkyl radicals (e.g. CH3-S-CH2-and C2H5-S-C2H4-), the radical C8H5-S-C6H4-(p), alkoxyaryl radicals (e.g. methoxyphenyl and ethoxynaphthyl) and alkyl-, halo-and nitro-substituted radicals (e.g. tolyl, xylyl, 2-chloroethyl, 3-bromopropyl, fluoromethyl, p-chlorophenyl, p-nitrophenyl, m-ethylphenyl, 2-nitroethoxymethyl and 2 : 4-dinitrobenzyl). Hydrazo-monocarboxylic esters of the formula H2N-NH-COOR1 are manufactured by reacting hydrazine hydrate with a carbonic ester R1OCOOR1 (e.g. diphenyl, diethyl or dibenzyl carbonate), preferably with stirring and slight heating.  Polychlorocarbonates of the second general formula above are manufactured by reacting a polyhydroxy compound with phosgene (preferably with excess of liquid phosgene below 10 DEG  C.) until all the hydroxy groups are substituted with chlorocarbonate radicals.  When the polyhydroxy compound is aromatic, it is necessary to work in the presence of a basic reagent (e.g. a tertiary amine such as pyridine or triethylamine, or an alkali or alkaline-earth metal hydroxide, carbonate or oxide such as sodium hydroxide or potassium carbonate.