反应详情

30 g of crude 4,6-dinitroresorcin were recrystallized in 1,500 g of ethanol to obtain 24.1 g of purified 4,6-dinitroresorcin. Next, 4.0 g of this purified 4,6-dinitroresorcin were added to methanol, and 0.0396 g of 5% palladium carbon (a 50% wet product) was then added thereto, followed by hydrogenation at 60° C. under an average hydrogen pressure of 0.8 MPaG. The reaction mass was poured into a 5% aqueous hydrochloric acid solution containing 6,000 ppm of stannous chloride, and then filtered to remove the catalyst. Afterward, analysis was carried out by HPLC, and it was confirmed that desired 4,6-diaminoresorcin was produced in a yield of 96.2 mol %. The solvent was removed from the filtrate by an evaporator to obtain the crystals of crude 4,6-dinitroresorcin. The crystals were dissolved in 21.3 g of water containing 0.32 g of stannous chloride, and 0.2 g of activated carbon was added to the solution. Thereafter, the solution was stirred for 30 minutes and then filtered to remove the activated carbon. When 16.0 g of 36% hydrochloric acid were gradually added dropwise to the filtrate, the gradual deposition of crystals was observed. The crystals were collected by filtration and then dried at 50° C. under reduced pressure to obtain 3.03 g (yield=46.4%) of 4,6-diaminoresorcin dihydrochloride.

1. additionwas then added
2. customfollowed by hydrogenation at 60° C. under an average hydrogen
3. filtrationfiltered
4. customto remove the catalyst
5. customwas produced in a yield of 96.2 mol %
6. customThe solvent was removed from the filtrate by an evaporator
7. customto obtain the crystals of crude 4,6-dinitroresorcin
8. additionwas added to the solution
9. filtrationfiltered
10. customto remove the activated carbon
11. additionWhen 16.0 g of 36% hydrochloric acid were gradually added dropwise to the filtrate
12. filtrationThe crystals were collected by filtration
13. customdried at 50° C. under reduced pressure