3971-31-1

121-91-5

3971-31-1

1. To a methanol (2.8 L) suspension containing isophthalic acid (500 g, 3 mol), 5% rhodium/alumina catalyst (50 g) and acetic acid (150 mL) were added sequentially. 2. The reaction mixture was subjected to a hydrogen atmosphere (50 psi) and shaken overnight at room temperature. 3. Upon completion of the reaction, the mixture was filtered through a diatomaceous earth pad to remove the catalyst. 4. Fresh 5% rhodium/alumina catalyst (25 g) was added to the filtrate. Fresh 5% rhodium/alumina catalyst (25 g) was added to the filtrate and the reaction was again shaken under hydrogen atmosphere (50 psi) for 24 h. 5. At the end of the reaction, the final reaction mixture was filtered through a pad of diatomaceous earth. 6. The filtrate was concentrated under reduced pressure to give 493 g of 1,3-cyclohexanedicarboxylic acid as white powder in 96.3% yield. 7. The product has a melting point of 163-165 °C. The melting point of the product was 163-165°C.