7-(2-bromoethyl)-3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione synthesis

Yield:23146-05-6 83%

Reaction Conditions:

Stage #1: theophyllinewith sodium hydride in N,N-dimethyl-formamide;mineral oil at 20; for 0.166667 h;
Stage #2: ethylene dibromide in N,N-dimethyl-formamide;mineral oil at 20; for 24 h;

Steps:

3.A A) Synthesis of 7-(2-bromoethyl)-1,3-dimethyl-3,7-dihydro-1H-purin-2,6-dione.

730 mg (18.3 mmoles) of NaH (60% in mineral oil) are added at room temperature to a solution of l,3-dimethyl-3,7-dihydro-lH-purin-2, 6-dione (theophylline) (IV) (3 g, 16.65 mmoles) in DMF (55 mL). The mixture is left under stirring for about 10 minutes, and 7.2 mL of dibromoethane (V) (83.25 mmoles) are then added dropwise. The mixture is left under stirring at room temperature for 24 hours; the reaction is then recovered by abundantly diluting with EtOAc and washing the organic phase with H₂0 (3x) and brine (lx). The organic phase is anhydrified, filtered and evaporated. A white solid is obtained after trituration with heptane (3.97 g, yield = 83%). LC-MS [M⁺H⁺] : 288.

References:

WO2020/157668,2020,A1 Location in patent:Page/Page column 51