Related Products of 219814-29-6,Some common heterocyclic compound, 219814-29-6, name is 2,5-Dibromo-4-methylimidazole, molecular formula is C4H4Br2N2, 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.
Step A : (5-Bromo-6-methyl-3 H- 1 ‘ -azaspiro [imidazo [2, 1 -b] oxazole-2,3 ‘ – bicyclo[2.2.2]octan]-l ‘-yl-8-ium)trihydroborate and (6-bromo-5-methyl-3H-l ‘- azaspiro[imidazo[2, l-b]oxazole-2,3 ‘-bicyclo[2.2.2]octan]- -yl-8-ium)trihydroborate To 2,4-dibromo-5-methyl-lH-imidazole (0.8 g, 3.3 mmol) in THF (25 niL) was added N-butyllithium (1.3 niL, 3.3 mmol) dropwise at -78C. After 45 minutes, a solution of racemic r-azaspiro[oxirane-2,3′-bicyclo[2.2.2]octan]-l’-yl-4- ium)trihydroborate (0.56 g, 3.7 mmol) from the reference example, in THF (20 mL) was added dropwise at -78C. The cooling bath was removed and the reaction mixture warmed to room temperature. After 15 minutes, the mixture was heated to 75C for 2 hours and then cooled to room temperature. The reaction was quenched with water and the product was extracted with ethyl acetate (100 mL). The organics were dried with MgS04, filtered and the solvent was removed to yield the crude product. The crude material was purified by chromatography (Biotage) to yield the regioisomeric products. These regioisomers were separated by reverse phase chromatography using a Sunfire column with gradients of acetonitrile-water containing 0.1% of trifluoroacetic acid (TFA), and at 40 mL/min flow rate. The pure fractions for peak 1 and peak 2 were then neutralized with 1 N NaOH (pH ~8-9) and the products were extracted with ethyl acetate. The organic layers were dried with MgS04, filtered and the solvent was removed to yield racemic (5-bromo-6-methyl-3H-l’-azaspiro[imidazo[2,l-b]oxazole-2,3′- bicyclo[2.2.2]octan]-l’-yl-8-ium)trihydroborate (0.32 g, 1.0 mmol, 30.8 % yield) XH NMR (500MHz, DMSO-d6) delta 4.23 (d, J=9.8 Hz, IH), 4.12 (d, J=9.9 Hz, IH), 3.36 (dd, J=15.2, 2.5 Hz, IH), 3.19 (dd, J=15.3, 2.1 Hz, IH), 3.04 – 2.95 (m, IH), 2.91 – 2.73 (m, 3H), 2.35 (br. s., IH), 2.03 – 1.88 (m, 4H), 1.84 – 1.67 (m, 3H), 1.64 – 1.11 (m, 3H). MS (LC/MS) R.T. = 2.09; [M+2]+ = 300.04 and racemic (6-bromo-5-methyl-3H-l’- azaspiro[imidazo[2,l-b]oxazole-2,3′-bicyclo[2.2.2]octan]-r-yl-8-ium)trihydroborate (0.33 g, 1.1 mmol, 31.7 % yield) as powders. NMR (500MHz, DMSO-de) delta 4.32 (d, J=10.1 Hz, IH), 4.12 (d, J=10.2 Hz, IH), 3.36 (d, J=2.4 Hz, IH), 3.18 (dd, J=15.2, 2.2 Hz, IH), 2.99 (d, J=2.9 Hz, IH), 2.93 – 2.78 (m, 3H), 2.31 (d, J=2.0 Hz, IH), 2.06 – 1.94 (m, 4H), 1.84 – 1.69 (m, 3H), 1.62 – 1.22 (m, 3H). MS (LC/MS) R.T. = 2.64; [M+2]+ = 300.04.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2,5-Dibromo-4-methylimidazole, its application will become more common.
Reference:
Patent; BRISTOL-MYERS SQUIBB COMPANY; COOK II, James H.; ZUSI, F. Christopher; HILL, Matthew D.; (87 pag.)WO2016/73407; (2016); A1;,
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem