Claims
- 1. The process for preparing N,N'-diphenyl- or N,N'-dialkylpyromellitdiimides which comprises the steps of:
- reacting N-phenyl-1-cyclohexene-1,2-dicarboximide with N-phenyl-maleimide or N-alkyl-1-cyclohexene-1,2-dicarboximide with N-alkyl-maleimide in substantially equimolar relationship under pyrolysis conversion conditions to the dimer of respectively N-phenyl-1,3-butadiene-2,3-dicarboximide and N,N'-diphenyl-3,4,5,6-tetrahydropyromellitdiimide or N-alkyl-1,3-butadiene-2,3-dicarboximide and N,N'-dialkyl-3,4,5,6-tetrahydropyromellitdiimide, wherein said pyrolysis conversion conditions include elevated temperatures in the range of about 500.degree. to 1000.degree. C., reduced pressure, and short contact time, effective for said pyrolysis conversion, and
- dehydrogenating under dehydrogenation conditions said N,N'-diphenyl- or N,N'-dialkyl-3,4,5,6-tetrahydropyromellitdiimide to said N,N'-diphenyl- or N,N'-dialkyl-pyromellitdiimide.
- 2. The process according to claim 1 wherein said dehydrogenating is conducted by heating said N,N'-diphenyl- or N,N'-dialkyl-3,4,5,6-tetrahydropyromellitdiimides with sulfur, thereby producing said N,N'-diphenyl-or N,N'-dialkyl-pyromellitdiimides.
- 3. The process according to claim 1 wherein said dehydrogenating is conducted by contacting said N,N'-diphenyl- or N,N'-dialkyl-3,4,5,6-tetrahydropyromellitdiimides with a palladium, platinum, or ruthenium dehydrogenation catalyst under effective dehydrogenation conditions, thereby producing said N,N'-diphenyl or N,N'-dialkyl-pyromellitdiimides.
- 4. The process according to claim 1 wherein said N,N'-diphenyl- or N,N'-dialkyl- is said N,N'-dialkyl.
- 5. The process according to claim 4 wherein said N,N'-dialkyl is N,N'-dimethyl.
Parent Case Info
This is a Divisional application of Ser. No. 802,168, filed May 31, 1977, now U.S. Pat. No. 4,125,536 patented Nov. 14, 1978; which is a Divisional application of Ser. No. 603,221, filed Aug. 8, 1975, now U.S. Pat. No. 4,056,542, patented Nov. 1, 1977; which is a Divisional application of Ser. No. 360,962, filed May 16, 1973, now U.S. Pat. No. 3,932,457, patented Jan. 13, 1976. Also see related Divisional application Ser. No. 935,195 filed Aug. 21, 1978, now U.S. 4,163,014 patented July 31, 1979.
Non-Patent Literature Citations (1)
Entry |
Jones et al., Chem. Abs. 82, 170575b (1975). |
Divisions (3)
|
Number |
Date |
Country |
Parent |
802168 |
May 1977 |
|
Parent |
603221 |
Aug 1975 |
|
Parent |
360962 |
May 1973 |
|