Research on new synthetic routes about 4-Fluoroindoline-2,3-dione

The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.

Electric Literature of 346-34-9, A common heterocyclic compound, 346-34-9, name is 4-Fluoroindoline-2,3-dione, molecular formula is C8H4FNO2, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.

Intermediate 1 A6-bromo-2-(trifluoromethyl)quinoline-4-carboxylic acid 300 mg (1.33 mmol) of 5-bromo-1 H-indole-2,3-dione was suspended in 3 mL water in a microwave vial. 82 mg ( 1.46 mmol) potassium hydroxide, 152 muL (2.65 mmol) acetic acid and 152 mg (1.86 mmol) sodium acetate were added so that the pH was around 5. The solution was cooled to 10 C and 238 muL (2.65 mmol) 1 ,1,1 -trifluoroacetone was added rapidly, the microwave vial was sealed and heated in the microwave for 2 h at 120 C. The reaction was stopped by the addition of 10% aqueous hydrochloric acid solution and the resulting precipitate was isolated by filtration, washed with water and dried in a vacuum drying cabinet at 50 C overnight to obtain 409 mg (1.28 mmol, 96%) of the desired title compound .1 H NMR (300 MHz, DMSO d6): delta (ppm) = 8.14 (dd, 1 H), 8.21 (d, 1 H), 8.32 (s, 1 H), 9.09 (d, 1 H), 14.50 (br. s. , 1 H)._In analogy to intermediate l, 300 mg (1.81 mmol) 4-fluoro-1H-indole-2,3-dione washeated with 326 pL (3.63 mmoL) 1,1,1-trifluoroacetone, 112 mg (1.99 mmoL)potassium hydroxide, 208 pL (3.63 mmo[) acetic acid and 209 mg (2.54 mmoL) sodium acetate in 3 mL water for 2 h at 100CC in the microwave to obtain 315 mg (1.22 mmol, 67%) of the desired title compound after aqueous work-up.1H NMR (400MHz, DMSO d6): 6 (ppm) = 783 -7.92 (m, 1 H), 8.09 (dd, 1 H), 8.25 (s, 1 H), 8.90 (dd, 1 H), 14.50 (br. 5., 1 H).

The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.

Reference:
Patent; BAYER PHARMA AKTIENGESELLSCHAFT; HEISLER, Iring; MUeLLER, Thomas; SIEBENEICHER, Holger; BUCHMANN, Bernd; CLEVE, Arwed; GUeNTHER, Judith; KOPPITZ, Marcus; HEROULT, Melanie; NEUHAUS, Roland; PETRUL, Heike; QUANZ-SCHOeFFEL, Maria; WO2015/91428; (2015); A1;,
Indoline – Wikipedia,
Indoline | C8H9N – PubChem