Overview | 1-chloro-2-(4-ethoxybenzyl)-4-iodobenzene is a key intermediate for the preparation of dapagliflozin. Dapaglizine is a sodium-glucose cotransporter 2(SGLT2) inhibitor used to treat type 2 diabetes, a C- aryl glucoside compound with the chemical name:(2S,3R,4R,5S,6R)-2-[3-(4-ethoxybenzyl)-4-chlorophenyl] -6-hydroxymethyltetrahydro-2H-pyran-3, 4, 5-triol. Dapaglifloin inhibits the reabsorption of blood sugar by inhibiting renal sodium-glucose cotransporter 2, thereby regulating blood sugar levels in the body; at the same time, it can significantly reduce the level of glycosylated hemoglobin and body weight of patients. |
preparation method | (1) mix 5.0 g4-bromophenyl ether and 100mL tetrahydrofuran, stir until clear, and set aside. (2) Add 0.64g of magnesium chips and 100mL of tetrahydrofuran in sequence, start stirring and fully mix, pour 20 mL4-bromophenyl ether tetrahydrofuran solution into it, heat up to 45 ℃, stop stirring after reaching the specified temperature, add 0.63g of elemental iodine particles, initiate reaction, and bubble overflow at the bottom of the system. When a large number of bubbles overflow, start stirring and slowly stirring until the system changes from dark red to colorless, clear and transparent, and the system temperature is significantly increased. (3) After adding 0.63g of elemental iodine particles, the normal rotation speed is restored, and the remaining tetrahydrofuran solution of 4-bromophenylether is added dropwise. The system temperature is kept in a micro-reflux state, and the dropwise addition is completed in 1-1.5 hours. After dropping, the microreflux reaction was maintained for 2 hours. Stop heating, cool to 0 ℃, add 0.47g cuprous iodide to the reaction kettle, and further cool to -20 ℃. (4) 8.24g of 2-(bromomethyl)-4-iodochlorobenzene were mixed in 100mL of tetrahydrofuran for later use. (5) When step (3) reaches the specified temperature of -20 ℃, the tetrahydrofuran solution of 2-(bromomethyl)-4-iodochlorobenzene is slowly added dropwise, and there is an obvious heating process in the middle stage of dropwise addition, and the reaction system is controlled to react at -20 ℃. The temperature rise is not obvious in the later stage of drip addition, and the drip addition is completed in 2 hours. After dropping, keep warm and stir for 2 hours. Stop cooling, naturally heat up to room temperature, and continue stirring for 12 hours. The system is quenched with 1N hydrochloric acid aqueous solution, the organic phase is extracted with ethyl acetate, distilled, concentrated to a small volume until crystallization, filtered, the filter cake is washed with pure water, and the air is dried. Weigh to obtain the target product (obtain the product 1-chloro-2-(4-ethoxybenzyl)-4-iodobenzene with a mass of 8.69g, a purity of 99.2%, and a yield of 93.11%). |