Adding a certain compound to certain chemical reactions, such as: 5910-12-3, name is 3-Bromopyrazolo[1,5-a]pyridine, belongs to bromides-buliding-blocks compound, 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 5910-12-3, SDS of cas: 5910-12-3
Part B begins with commercially available bromo-pyrazolopyrimidine 47 (755 mg, 3.83 mmol) and 4,4,5,5-tetramethyl-2-(propan-2-yloxy)-l,3)2-dioxaborolane (2.3 mL, 11.50 mmol) in THF (1.5 mL) at -78 0C. To this solution was added n-butyllithium (4.8 mL, 7.66 mmol) dropwise over 10 minutes. The reaction was slowly warmed to room temperature and was poured into water (10 mL) and partitioned with dichloromethane (10 mL). The organic was dried over sodium sulfate and concentrated before purification by column chromatography (0- 20% ethyl acetate in hexanes) to yield the boronic ester 48 (18% yield, 170 mg). 1H NMR (500 MHz, cdcl3) delta 8.54 – 8.44 (m, OH), 8.03 (s, 1 H), 7.65 (s, 1 H), 7.62 (d, J – 8.8, 1 H), 6.89 (d, J – 7.2, 1 H), 6.72 (x, J ‘ 54.4, 1 H), 6.20 (d, J = 9.3, 1 H), 4.37 – 4.06 (m, 1 H), 2.80 (t, J = 9.7, 1 H), 2.31 – 2.20 (m, IH), 2.10 (d, J = 13.7, IH), 1.92 – 1.73 (m, J = 26.0, 13.5, 2H), 1.44 – 1.16 (m, 2H).; Scheme 10.Stop A.Molecules of type 50 were prepared according to scheme 10 with the synthesis of compounds 46 and 48. Compound 46 (step A) was synthesized from commercially available dibromide 44. Regioselective metal-exchange followed by DMF quench provided aldehyde 46. Aldehyde 46 was reacted with excess deoxofluor to furnish compound 46. Preparation of boronic ester 48 (step B) was accomplished from commercial starting material (compound 47) via lithium-halogen exchange in the presence of 4,4,5>5-tetramethyl-2-(propan-2-yloxy)-l,3ยป2- dioxaborolane. Palladium-mediated coupling of 46 and 48 was followed by saponifcation to yield carboxylic acid 49. Amide formation with intermediate Il and subsequent deprotection provided compound 50.
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3-Bromopyrazolo[1,5-a]pyridine, and friends who are interested can also refer to it.
Reference:
Patent; MERCK & CO., INC.; KATZ, Jason; KNOWLES, Sandra, L.; JEWELL, James, P.; SLOMAN, David, L.; STANTON, Matthew, G.; NOUCTI, Njamkou; WO2010/17046; (2010); A1;,
Bromide – Wikipedia,
bromide – Wiktionary