Introduction of a new synthetic route about 5-Bromoimidazo[1,2-a]pyridine-2-carbaldehyde

At the same time, in my other blogs, there are other synthetic methods of this type of compound,878197-68-3, 5-Bromoimidazo[1,2-a]pyridine-2-carbaldehyde, and friends who are interested can also refer to it.

Adding a certain compound to certain chemical reactions, such as: 878197-68-3, 5-Bromoimidazo[1,2-a]pyridine-2-carbaldehyde, can increase the reaction rate and produce products with better performance than those obtained under traditional synthetic methods. Here is a downstream synthesis route of the compound, Formula: C8H5BrN2O, blongs to pyridine-derivatives compound. Formula: C8H5BrN2O

The reactor is charged with N-methylpiperazine (3.1 Kg, 31 mol ) and tetrahydrofuran (10 Liters) and stirred under nitrogen while cooling to negative 20 0C. n-Butyl lithium (10.4 L, 26.0 mol) is added to the reaction at a rate to maintain the negative 20 0C temp and the contents are stirred for 15 to 30 minutes. A slurry of 5- bromoimidazo[1 ,2-a]pyridine-2-carbaldehyde (2.79 Kg, 12.4 mol) in tetrahydrofuran (10 Liters) is added at a rate to maintain the reaction at ?0C. The slurry is washed in with additional tetrahydrofuran (6 Liters). The reaction is stirred for 30 minutes and warmed to approximately negative 10 0C. The reaction is quenched by addition of 6N HCI solution to achieve pH 4.0 while maintaining at ? 150C. The reaction is diluted with heptane (14 Liters) and the layers allowed to separate. The lower aqueous layer is drained and the upper organic layer is washed with 1 N HCI (2 x 1.5 Liters). The combined aqueous layers are stirred at 20 degrees and adjusted to pH 9 with 4N NaOH solution. The Aqueous layer is extracted with 10% iPrOH/CH2CI2 (3 x 28 Liters) and the combined organic layers are washed with saturated NaHCO3 solution (14 Liters) and evaporated at <25 0C to approximately 3 volumes, lsopropanol (28 Liters) is added and reaction again concentrated under reduced pressure to approximately 8.5 Liters, lsopropanol (17 Liters) is added and the reaction is treated with a solution of oxalic acid (1.0 Kg, 11.1 mol) in isopropanol (7 Liters) at a rate to maintain good stirring and temperature between approximately 25-4O0C. The reaction is stirred for 30 minutes and the solids are collected and washed with isopropanol (8.5 Liters) Solids are dried at 50 0C to yield 5-(4-methyM- piperazinyl)imidazo[1 ,2-a]pyridine-2-carbaldehyde, (2.25 Kg, 54% yield) 1 H NMR (400 MHz, DMSO-D6) delta ppm 10.01 (s, 1 H) 8.47 (s, 1 H) 7.41 (m, 2 H) 6.65 (m, 1 H) 3.34 (s, 8 H) 2.78 (s, 3 H) At the same time, in my other blogs, there are other synthetic methods of this type of compound,878197-68-3, 5-Bromoimidazo[1,2-a]pyridine-2-carbaldehyde, and friends who are interested can also refer to it. Reference:
Patent; SMITHKLINE BEECHAM CORPORATION; WO2006/26703; (2006); A2;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem