Method for production of maleimides

Claim 1

A method for the production of a maleimide of formula II: ##STR7## wherein R is a member selected from the group consisting of alkyl of 1-20 carbon atoms, phenyl, benzyl, cyclohexyl, pyridyl, quinolyl and the said moieties when substituted by halogen, carboxyl or nitro which comprises the sequential steps of (a) reacting maleic anhydride with a primary amine of the formula NH 2 -R wherein R is as defined above to form the corresponding maleinamic acid and (b) heating said maleinamic acid in a water insoluble or water immiscible inert non-polar organic solvent said solvent being utilized in a ratio by volume of from about 1 to about 20 to 1 with respect to said maleinamic acid in the presence of a primary amine acid addition salt catalyst, in an amount of about 2 to about 400 mol % of acid addition component, based on said maleinamic acid, formed from said primary amine and a strong inorganic or organic acid, said salt containing said acid addition component in an amount of less than 60 mol %, at a temperature of from about 120° to 250° C. and continuously distilling off the thus formed water as a mixture with said solvent.

Claim 2

A method for the production of a maleimide of formula II: ##STR7## wherein R is a member selected from the group consisting of alkyl of 1-20 carbon atoms, phenyl, benzyl, cyclohexyl, pyridyl, quinolyl and the said moieties when substituted by halogen, carboxyl or nitro which comprises the sequential steps of (a) reacting maleic anhydride with a primary amine of the formula NH 2 -R wherein R is as defined above to form the corresponding maleinamic acid and (b) heating said maleinamic acid in a water insoluble or water immiscible inert non-polar organic solvent said solvent being utilized in a ratio by volume of from about 1 to about 20 to 1 with respect to said maleinamic acid in the presence of a primary amine acid addition salt catalyst, in an amount of about 2 to about 400 mol % of acid addition component, based on said maleinamic acid, formed from said primary amine and a strong inorganic or organic acid, said salt containing said acid addition component in an amount of less than 60 mol %, at a temperature of from about 120° to 250° C. and continuously distilling off the thus formed water as a mixture with said solvent.

Claim 6

A method for the production of a maleimide of formula II: ##STR8## wherein R is a member selected from the group consisting of alkyl of 1-20 carbon atoms, phenyl, benzyl, cyclohexyl, pyridyl, quinolyl and the said moieties when substituted by halogen, carboxyl or nitro which comprises the sequential steps of: (a) reacting maleic anhydride with a primary amine of the formula NH 2 -R wherein R is as defined above to form the corresponding maleinamic acid and (b) heating said maleinamic acid in a water insoluble or water immiscible inert non-polar organic solvent said solvent being utilized in a ratio by volume of from about 1 to about 20 to 1 with respect to said maleinamic acid in the presence of a catalyst supported on a solid inert organic or inorganic carrier, said catalyst containing an acid component in an amount of about 2 to about 400 mol % of acid component, based on said maleinamic acid, at least one catalyst ingredient being selected from the group consisting of (a) a strong organic or inorganic acid, (b) an amine acid addition salt produced from said primary amine and a strong inorganic or organic acid, and (c) a mixture of said amine acid addition salt and a strong acid, at a temperature of from about 120° to 250° C. and continuously distilling off the thus formed water as a mixture with said solvent.

Claim 7

A method for the production of a maleimide of formula II: ##STR8## wherein R is a member selected from the group consisting of alkyl of 1-20 carbon atoms, phenyl, benzyl, cyclohexyl, pyridyl, quinolyl and the said moieties when substituted by halogen, carboxyl or nitro which comprises the sequential steps of: (a) reacting maleic anhydride with a primary amine of the formula NH 2 -R wherein R is as defined above to form the corresponding maleinamic acid and (b) heating said maleinamic acid in a water insoluble or water immiscible inert non-polar organic solvent said solvent being utilized in a ratio by volume of from about 1 to about 20 to 1 with respect to said maleinamic acid in the presence of a catalyst supported on a solid inert organic or inorganic carrier, said catalyst containing an acid component in an amount of about 2 to about 400 mol % of acid component, based on said maleinamic acid, at least one catalyst ingredient being selected from the group consisting of (a) a strong organic or inorganic acid, (b) an amine acid addition salt produced from said primary amine and a strong inorganic or organic acid, and (c) a mixture of said amine acid addition salt and a strong acid, at a temperature of from about 120° to 250° C. and continuously distilling off the thus formed water as a mixture with said solvent.

Claim 11

A method for the production of a maleimide of formula II: ##STR9## wherein R is a member selected from the group consisting of alkyl of 1-20 carbon atoms, phenyl, benzyl, cyclohexyl, pyridyl, quinolyl and the said moieties when substituted by halogen, carboxyl or nitro which comprises the sequential steps of: (a) reacting maleic anhydride with a primary amine of the formula NH 2 -R wherein R is as defined above to form the corresponding maleinamic acid, (b) heating said maleinamic acid in a water insoluble or water immiscible inert non-polar organic solvent, said solvent being utilized in a ratio by volume of from about 1 to about 20 to 1 with respect to said maleinamic acid in the presence of a metal containing compound selected from the group consisting of oxides, acetates, maleates, succinates, nitrates, phosphates, chlorides and sulfates of a metal selected from the group consisting of zinc, chromium, palladium, cobalt, nickel iron and aluminum and a stabilizer selected from the group consisting of methoxy benzoquinone, p-methoxyphenol, phenothiazine, hydroquinone, alkylated diphenyl amines, methylene blue, tert-butyl catechol, tert-butyl hydroquinone, zinc dimethyldithiocarbamate, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, thiodipropionic ester, mercaptobenzimidazole, triphenyl phosphite, alkylphenols and alkylbisphenols, and in the presence of said primary amine acid addition salt catalyst, in an amount of about 2 to about 400 mol % of acid addition component, based on said maleinamic acid, formed from said primary amine and a strong inorganic or organic acid, said salt containing said acid addition component in an amount of less than 60 mol % at a temperature of from about 120° to 250° C. and continuously distilling off the thus formed water as a mixture with said solvent.

Claim 12

A method for the production of a maleimide of formula II: ##STR9## wherein R is a member selected from the group consisting of alkyl of 1-20 carbon atoms, phenyl, benzyl, cyclohexyl, pyridyl, quinolyl and the said moieties when substituted by halogen, carboxyl or nitro which comprises the sequential steps of: (a) reacting maleic anhydride with a primary amine of the formula NH 2 -R wherein R is as defined above to form the corresponding maleinamic acid, (b) heating said maleinamic acid in a water insoluble or water immiscible inert non-polar organic solvent, said solvent being utilized in a ratio by volume of from about 1 to about 20 to 1 with respect to said maleinamic acid in the presence of a metal containing compound selected from the group consisting of oxides, acetates, maleates, succinates, nitrates, phosphates, chlorides and sulfates of a metal selected from the group consisting of zinc, chromium, palladium, cobalt, nickel iron and aluminum and a stabilizer selected from the group consisting of methoxy benzoquinone, p-methoxyphenol, phenothiazine, hydroquinone, alkylated diphenyl amines, methylene blue, tert-butyl catechol, tert-butyl hydroquinone, zinc dimethyldithiocarbamate, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, thiodipropionic ester, mercaptobenzimidazole, triphenyl phosphite, alkylphenols and alkylbisphenols, and in the presence of said primary amine acid addition salt catalyst, in an amount of about 2 to about 400 mol % of acid addition component, based on said maleinamic acid, formed from said primary amine and a strong inorganic or organic acid, said salt containing said acid addition component in an amount of less than 60 mol % at a temperature of from about 120° to 250° C. and continuously distilling off the thus formed water as a mixture with said solvent.

Claim 15

A method for the production of a maleimide of formula II: ##STR10## wherein R is a member selected from the group consisting of alkyl of 1-20 carbon atoms, phenyl, benzyl, cyclohexyl, pyridyl, quinolyl and the said moieties when substituted by halogen, carboxyl or nitro which comprises the sequential steps of: (a) reacting maleic anhydride with a primary amine of the formula NH 2 -R wherein R is as defined above to form the corresponding maleinamic acid, (b) heating said maleinamic acid in a water insoluble or water immiscible inert non-polar organic solvent, said solvent being utilized in a ratio by volume of from about 1 to about 20 to 1 with respect to said maleinamic acid in the presence of a metal containing compound selected from the group consisting of oxides, acetates, maleates, succinates, nitrates, phosphates, chlorides and sulfates of a metal selected from the group consisting of zinc, chromium, palladium, cobalt, nickel, iron and aluminum and a stabilizer selected from the group consisting of methoxy benzoquinone, p-methoxyphenol, phenothiazine, hydroquinone, alkylated diphenyl amines, methylene blue, tert-butyl catechol, tert-butyl hydroquinone, zinc dimethyldithiocarbamate, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, thiodipropionic ester, mercaptobenzimidazole, triphenyl phosphite, alkylphenols and alkylbisphenols, and in the presence of a catalyst supported on a solid inert organic or inorganic carrier said catalyst containing an acid component in an amount of about 2 to about 400 mol % of acid component, based on said maleinamic acid, at least one catalyst ingredient being selected from the group consisting of (a) a strong organic or inorganic acid, (b) an amine acid addition salt produced from said primary amine and a strong inorganic or organic acid, and (c) a mixture of said amine acid addition salt and a strong acid at a temperature of from about 120° to 250° C. and continuously distilling off the thus formed water as a mixture with said solvent.

Claim 16

A method for the production of a maleimide of formula II: ##STR10## wherein R is a member selected from the group consisting of alkyl of 1-20 carbon atoms, phenyl, benzyl, cyclohexyl, pyridyl, quinolyl and the said moieties when substituted by halogen, carboxyl or nitro which comprises the sequential steps of: (a) reacting maleic anhydride with a primary amine of the formula NH 2 -R wherein R is as defined above to form the corresponding maleinamic acid, (b) heating said maleinamic acid in a water insoluble or water immiscible inert non-polar organic solvent, said solvent being utilized in a ratio by volume of from about 1 to about 20 to 1 with respect to said maleinamic acid in the presence of a metal containing compound selected from the group consisting of oxides, acetates, maleates, succinates, nitrates, phosphates, chlorides and sulfates of a metal selected from the group consisting of zinc, chromium, palladium, cobalt, nickel, iron and aluminum and a stabilizer selected from the group consisting of methoxy benzoquinone, p-methoxyphenol, phenothiazine, hydroquinone, alkylated diphenyl amines, methylene blue, tert-butyl catechol, tert-butyl hydroquinone, zinc dimethyldithiocarbamate, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, thiodipropionic ester, mercaptobenzimidazole, triphenyl phosphite, alkylphenols and alkylbisphenols, and in the presence of a catalyst supported on a solid inert organic or inorganic carrier said catalyst containing an acid component in an amount of about 2 to about 400 mol % of acid component, based on said maleinamic acid, at least one catalyst ingredient being selected from the group consisting of (a) a strong organic or inorganic acid, (b) an amine acid addition salt produced from said primary amine and a strong inorganic or organic acid, and (c) a mixture of said amine acid addition salt and a strong acid at a temperature of from about 120° to 250° C. and continuously distilling off the thus formed water as a mixture with said solvent.