Patent GB-946177-A (GB)
Title: Production of ª ,ª -unsaturated aliphatic isocyanates and carbamyl halides
Inventor: KOENIG KARL-HEINZ
IPC: C07C263/16
Filed: 1962-05-24
Abstract: a , b -Unsaturated isocyanates and carbamyl halides are obtained by the removal of hydrogen halide (see below) from compounds of formula RNCO or RR1NCOY, where Y is Cl or Br; R is a C2-10 hydrocarbon radical attached to the N atom by an aliphatic carbon atom, and carrying, at the a -carbon atom and at least one aliphatic b -carbon atom (singly bonded to the a -carbon atom), at least one hydrogen and/or at least one chlorine and/or at least one bromine atom, such that the a - and b -carbon atoms contain at least one hydrogen and at least one halogen atom on the adjacent carbon atoms; R1 has the same meaning as R, or is hydrogen or CR113, where R11 is H, Cl or Br, or R and R1 together represent a 5-7-membered ring including the nitrogen atom and possibly another nitrogen or oxygen atom, the ring being substituted by hydrogen and chlorine and/or bromine on the a - and b -carbon atoms; the removal of hydrogen halide being achieved by heating the starting compound at 80-400 DEG C. or by contacting it at 0-400 DEG C. with a substance promoting the elimination of hydrogen halide. Preferably R is a C2-4 alkyl radical substituted by 1-8 chlorine or bromine atoms, or by a C6-8 aryl radical and 1-7 chlorine or bromine atoms. Preferably the catalyst is a material of large surface area, e.g. active carbon, pumice, silica gel, bleaching clays, asbestos, clays and aluminium hydrosilicates, which may be impregnated with a halide of an alkali or alkaline earth metal or Al, FeCl3, or an oxide of Sn, Th or Al in an amount of 3-30% by weight based on the large-surfaced material.  Novel compounds.  The following are claimed per se:-compounds R1NCO and R1NHCOY, where Y is chlorine or bromine and R1 is a C2-4 alkenyl radical, the double bond being in the a , b -position to the N atom, substituted by 1-7 chlorine or bromine atoms, or by a C6-8 aryl radical and possibly by up to 6 chlorine or bromine atoms.  Examples prepare (1) and (6) a dichlorovinyl isocyanate from trichloroethyl (probably 1, 1,2-) isocyanate; (2) 1-chlorovinyl isocyanate; (3) a mixture of isopropenyl isocyanate and isopropenyl carbamyl chloride; (4)  a mixture of isopropenyl isocyanate and isopropenyl carbamyl bromide; (5) 1-phenylvinyl isocyanate; (7) 1,1,3,3-tetrachloropropen-(1)-yl isocyanate-(2); (8) N, N-divinyl carbamyl chloride; and (9) chlorinated unsaturated morpholyl carbamyl chloride. Other products and suitable starting materials (which may be obtained by reacting suitable amines with phosgene, or by halogenating aliphatic or heterocyclic carbamyl halides or aliphatic isocyanates) are listed. The product isocyanates may be converted to the carbamyl halides by treatment with HCl or HBr, and carbamyl halides may be converted into isocyanates by single or repeated distillation.ALSO:1-Phenylvinyl isocyanate is copolymerized with methyl acrylate in amounts of 5-25% by weight, in cyclohexane and in the presence of 0.5% by weight, based on the monomers, of a , a 1-azo-bis-isobutyronitrile at 60-70 DEG C., the resulting solution is cooled and mixed with a cross-linking agent such as a diol or diamine. It is stated that other a ,b -unsaturated isocyanates and carbamyl halides, of formula R1NCO and R1NHCOY, where Y is Cl or Br and R1 is an a ,b -unsaturated C2- 4 alkenyl radical substituted by 1-7 chlorine or bromine atoms, or by a C6- 8 aryl radical and possibly by up to 6 chlorine or bromine atoms, may be used in place of the phenylvinyl isocyanate.ALSO:Paper is coated by a solution obtained by copolymerizing 1-phenylvinyl isocyanate with methyl acrylate in cyclohexane and adding a diol or diamine (see Division C3).