Process for producing 5-nitro-3,4-dihydro-1(H)-naphthalinone, 1,5-naphthalenediamine and 1,5-naphthalene diisocyanate
The present invention relates to a process for producing 5-nitro-3,4-dihydro-1(2H)-naphthalinone, 1,5-naphthalenediamine and 1,5-naphthalene diisocyanate, in which 4-(2-nitrophenyl)-n-butyronitrile is converted to 4-(2-nitrophenyl)-n-butyric acid.
1. A process for producing 1,5-naphthalene diisocyanate comprising the steps of:
reacting 4-(2-nitrophenyl)-n-butyronitrile with an acid or a base to produce 4-(2-nitrophenyl)-n-butyric acid;
optionally chlorinating the 4-(2-nitrophenyl)-n-butyric acid to produce 4-(2-nitrophenyl)-n-butyryl chloride;
cyclizing the 4-(2-nitrophenyl)-n-butyric acid or the 4-(2-nitrophenyl)-n-butyryl chloride to produce 5-nitro-3,4-dihydro-1(2H)-naphthalinone;
aminating the 5-nitro-3,4-dihydro-1(2H)-naphthalinone to produce 5-nitro-3,4-dihydro-1(2H)-naphthylamine or the tautomeric 5-nitro-3,4-dihydro-1(2H)-naphthylimine;
aromatizing the 5-nitro-3,4-dihydro-1(2H)-naphthylamine or the tautomeric 5-nitro-3,4-dihydro-1(2H)-naphthylimine to produce 5-nitro-1-naphthylamine and/or 5-nitroso-1 -naphthylamine;
hydrogenating the 5-nitro-1-naphthylamine and/or 5-nitroso-1-naphthylamine to produce 1,5-naphthalenediamine; and
reacting the 1,5-naphthalenediamine with phosgene to produce 1,5-naphthalene diisocyanate.
2. The process of claim 1 , wherein the acid in the step of reacting is selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, hydrogen sulfates and dihydrogen phosphates.
3. The process of claim 1 , wherein the base in the step of reacting is selected from the group consisting of oxides, hydroxides and carbonates of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, stmntium, barium or aluminum and mixtures thereof, aqueous solutions or suspensions of hydroxides and carbonates of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium or aluminum.
4. The process of claim 1 , wherein the step of cyclization occurs in the presence of at least one member selected from the group consisting of aluminum trichloride, boron trifluoride, sulfuric acid, phosphoric acid, polyphosphoric acid, phosphorus pentoxide, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, niobic acid and mixtures of antimony pentafluoride and fluorosulfuric acid.
5. The process of claim 1 , wherein the optional step of chlorination occurs in the presence of at least one chlorinating agent selected from the group consisting of chlorine, thionyl chloride, phosgene, phosphoryl chloride, phosphorus trichloride and phosphorus pentachloride.
6. The process of claim 1 , wherein the step of amination occurs by reaction with ammonia, optionally in the presence of an ammonium salt.
7. The process of claim 1 , wherein the 4-(2-nitrophenyl)-n-butyronitrile is prepared by reacting ortho-nitrotoluene and acrylonitrile in the presence of a base.