Oxygen → Tetrahydrophthalic anhydride

3Me--THPA was produced by the liquid phase aeration method. Thus, the air in a 300 ml four-necked flask similar to the one used in Example 5 was replaced with nitrogen and, then, the flask was charged with 98 g of maleic anhydride, 300 ppm of p-tert-butylcatechol by way of auxiliary polymerization inhibitor and 800 ppm of dilauryl thiodipropionate by way of auxiliary polymerization inhibitor and the charge was melted at 60° C. Then, the internal atmosphere of the reaction system was replaced with nitrogen gas, and thereafter nitrogen gas containing 1 volume % of oxygen was passed into the reaction mixture at a rate of 5 ml/min throughout the reaction. Under this atmosphere, 374 g of crude trans-1,3-pentadiene of the same composition as that used in Example 1 was continuously added at 60° C. for 4 hours. Major portion of unreactive fractions was distilled off from the reaction mixture in the course of reaction. Thereafter, the reaction mixture was treated in the same manner as in Example 5 to give 164 g of 3Me--THPA. The investigation revealed no gels in the product.

1. customThus, the air in a 300 ml four-necked flask similar to the one used in Example 5
2. customwas passed into the reaction mixture at a rate of 5 ml/min throughout the reaction
3. additionwas continuously added at 60° C. for 4 hours
4. distillationMajor portion of unreactive fractions was distilled off from the reaction mixture in the course of reaction
5. additionThereafter, the reaction mixture was treated in the same manner as in Example 5

ORD-Eintrag

ord-a2b09e0aab0147408fda825908cb4e7e

Quelldatensatz

uspto-grants-1993_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05237074