CYCLOHEXANE-1 2 4 5-TETRACARBOXYLIC ACI&

White crystal

34.3 g of commercially available pyromellitic dianhydride (GC analysis purity: 98.2percent) was charged into 500 mL high pressure kettle, meanwhile 250 mL of deionized water and 2.5 g of a 5 wtpercent Pd-C catalyst as a precious metal catalyst were added, then the hydrogen gas was introduced into the high pressure kettle (autoclave) and the hydrogen pressure was controlled at 2MPa, the temperature was controlled at 33 ° C ± 1 ° C, and carried the reaction for 2h. [0024] And then cooled to room temperature (15 ° C ~ 25 ° C, the same below) to discharge the filter, the filter cake separated Pd-C catalyst, this catalyst was placed in air overnight after that it can be recycled for the next batch of catalytic hydrogenation reaction. After the filtrate was distilled off, hydrogenated pyromellitic acid wass precipitated; Filtered again, and the filter cake was subjected to decolourization and purification using deionized water and activated carbon and then obtained 38.8g of white solid hydrogenated pyromellitic acid, the yield was 99.1percent, GC analysis was 99.46percent.Made from Hastelloy with an internal volume of 5 liters (HC 22)An autoclave was charged with 552 g of pyromellitic acid, 200 g of a catalyst in which rhodium was supported on activated carbon (manufactured by N. E. Chemcat Corporation)1656 g of water was charged, The inside of the reactor was replaced with nitrogen gas while stirring.Subsequently, the interior of the reactor was replaced with hydrogen gas, The temperature was raised to 60 ° C. with the hydrogen pressure in the reactor set at 5.0 MPa.The reaction was carried out for 2 hours while keeping the hydrogen pressure at 5.0 MPa. Hydrogen gas in the reactor was replaced with nitrogen gas, The reaction solution was withdrawn from the autoclave, The reaction solution was filtered while hot to separate the catalyst.The filtrate was concentrated by evaporating water under reduced pressure with a rotary evaporator, Crystals were precipitated.The precipitated crystal was subjected to solid-liquid separation at room temperature, And dried to obtain 481 g (yield: 85.0percent) of 1, 2, 4, 5-cyclohexanetetracarboxylic acid.In a 2L three-necked flask equipped with a mechanical stirrer, reflux condenser, trap, and thermometer, 400 g of hydrogenated tetrahydrophthalic acid ethyl ester, 140 g of concentrated sulfuric acid, and 1200 mL of deionized water are added and heated to 120-125°C to incubate the reaction 16- 24h, During the reaction, water and ethanol were continuously separated. No ethanol was distilled off by GC and the reaction was stopped at room temperature.Crystallization and suction filtration afforded 223 g of hydrogenated pyromellitic acid as a white solid, yield: 80percent.

Molecular Weight:260.20
XLogP3:-1.2
Hydrogen Bond Donor Count:4
Hydrogen Bond Acceptor Count:8
Rotatable Bond Count:4
Exact Mass:260.05321734
Monoisotopic Mass:260.05321734
Topological Polar Surface Area:149
Heavy Atom Count:18
Complexity:327
Undefined Atom Stereocenter Count:4
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes