Claims
- 1. A process for preparing a bisimide suitable for preparing a bis(ether anhydride) wherein the process comprises
- (a) providing a N-alkyl nitrophthalimide and a bisphenol alkali metal salt;
- (b) reacting the N-alkyl nitrophthalimide and said salt at a solids level of at least about 30% by weight solids to form a substantially pure bisimide; and
- (c) extracting the bisimide.
- 2. A process according to claim 1 wherein the N-alkyl nitrophthalimide and said bisphenol salt are reacted in substantially solventless conditions.
- 3. A process according to claim 1 wherein the N-alkyl nitrophthalimide has a solubility in toluene of about 11% by weight or greater at room temperature and a melting temperature in the range of about 90 to about greater than 135.degree. C.
- 4. A process according to claim 1 wherein the N-alkyl nitrophthalimide has a solubility in toluene of about 50% by weight or greater at room temperature and a melting temperature in the range of about 90 to about greater than 135.degree. C.
- 5. A process according to claim 1 wherein the N-alkyl nitrophthalimide is a C.sub.3 -C.sub.6 alkyl nitrophthalimide.
- 6. A process according to claim 1 wherein the N-alkyl nitrophthalimide is an N-propyl, N-butyl or N-hexyl nitrophthalimide.
- 7. A process according to claim 2 wherein the bisimide is extracted in an alkali solution at a temperature of 85.degree. C. or less.
- 8. The process according to claim 1, further comprising
- (d) performing an exchange reaction by reacting said bisimide of (c) with a phthalic anhydride.
- 9. The process of claim 8, further comprising
- (e) isolating the bisanhydride product from said exchange reaction (d).
- 10. The process of claim 8, wherein the percent solids in said exchange reaction and purification is greater than about 40%.
- 11. The process of claim 10, wherein the percent solids in said exchange reaction and purification is greater than about 60%.
Parent Case Info
This is a divisional of application Ser. No. 08/964,032 filed on Nov. 4, 1997, now U.S. Pat. No. 5,936,099 which is a divisional of Ser. No. 08/652,067 filed on May 23, 1996 issued on Feb. 17, 1998 U.S. Pat. No. 5,719,295, which is a divisional of Ser. No. 08/250,736 filed on May 27, 1994, issued on Jul. 16, 1996 U.S. Pat. No. 5,536,846.
US Referenced Citations (15)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0 273 159 A1 |
Jul 1988 |
EPX |
Non-Patent Literature Citations (3)
Entry |
CA 84:121421f Nitro derivatives of aromatic compounding; Cook et al., p. 505, 1976. |
CA 84: 12146h N-methyl nitro phthalimides; Cook et al. p. 524, 1976. |
CSA 119: 20329t Preparaton of 4-nitro-N-methyl phthalimide, Dorogov et al., p. 881, 1993. |
Divisions (3)
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Number |
Date |
Country |
Parent |
964032 |
Nov 1997 |
|
Parent |
652067 |
May 1996 |
|
Parent |
250736 |
May 1994 |
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