Application In Synthesis of 5-Aminoisoindoline-1,3-dione,The dynamic chemical diversity of the numerous elements, ions and molecules that constitute the basis of life provides wide challenges and opportunities for research.
The synthesis of bromoacetal 6 from phthalimide (7) is shown in FIG. 11. Based on reactions described in the literature, these transformations were carried out on large scale, and some steps were improved. Nitration of 200 g of phthalimide (7) gives 146 g of 5-nitrophthalimide (8). Reduction of 8 by catalytic hydrogenation, according to the literature procedure, is a bottleneck in the synthesis because of the large volume of solvent needed. With a 2 L Parr hydrogenator pressure vessel, 30 g of 8 is converted to 25 g of amine 9. The next step is also a reduction; aminophthalide 10 is obtained quantitatively from 9 by copper-catalyzed reaction with zinc in aqueous base. Steps b and c could be combined by treating 8 with zinc dust and copper(II) sulfate in 2 M aq. sodium hydroxide. This variation, which is not shown in FIG. 11, removes the bottleneck, potentially allowing 100 g of 10 to be prepared in one step from 146 g of 9. The reaction conditions for the steps shown in FIG. 11 are as follows: a) HNO3, H2SO4, 0 C., 56% ; b) 5% Pd/C, H2, EtOAc, 97% ; c) Zn, CuSO4, 6 M NaOH, 5 C. then heated at 70-80 C. 16 h, 100% ; d) NaNO2, 4 M HBr, followed by CuBr at 0 C.; e) DIBAL, toluene, -42 C.; f) BF3 OEt2, MeOH, RT.
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 5-Aminoisoindoline-1,3-dione, and friends who are interested can also refer to it.
Reference:
Patent; Bell, Thomas W.; Cline, Joseph I.; Cremo, Christine R.; Gillett, Stephen L.; Frederick, John H.; US2011/77394; (2011); A1;,
Indoline – Wikipedia,
Indoline | C8H9N – PubChem