In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 2302-25-2 as follows. 2302-25-2
Step 1: To a stirred mixture of DMF (15 mL) and NaH (60% dispersion in mineral oil, 539 mg, 21 mmol) at 0C under argon was added 4-bromo-1H-imidazole (3 g, 20 mmol) in one portion. The mixture was stirred for 5 min at 0C. A solution of 2-(trimethylsilyl)ethoxymethyl chloride (4.3 mL, 24 mmol) in DMF (3 mL) was added dropwise. Afterstirring at 0 C for 1 h, the mixture was warmed slowly to rt and stirred for 6 h. The mixture was then partitioned betweenEtOAc (100 mL) and water (50 mL). The EtOAc layer was separated and washed with brine, dried over Na2SO4, filtered,and the filtrate was concentrated under reduced pressure. The residue was purified via silica gel flash chromatography(eluting with a gradient of 100% hexanes to 100% EtOAc) to afford a regioisomeric mixture of 4-bromo-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazole and 5-bromo-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazole as an oil (2.9 g, 53%). Step 2: To a mixture of 4-bromo-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazole and 5-bromo-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazole (345 mg, 1.3 mmol) from Step 1 of this Example, and 1-methylpyrazole-4-boronicacid pinacol ester (390 mg, 1.9 mmol) in DME (3 mL) was added K2CO3 (691, 5 mmol). Argon was bubbled into themixture for 5 min followed by the addition of Pd(PPh3)2Cl2 (44 mg, 0.06 mmol). Argon was bubbled into the mixture foran additional 5 min. Then the reaction vessel was sealed and the mixture was heated at 100 C for 15 h. The mixturewas cooled to rt, then partitioned between EtOAc (100 mL) and water (50 mL). The EtOAc layer was separated andwashed with brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified viasilica gel flash chromatography eluting with a gradient of 100% CH2Cl2 to 10% MeOH in CH2Cl2 to afford a regioisomericmixture of 1-methyl-4-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-4-yl)-1H-pyrazole and 1-methyl-4-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-5-yl)-1H-pyrazole as an oil (280 mg, 82%). LCMS (ESI) m/z 280 (M+H)+. Step 3: A mixture of 1-methyl-4-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-4-yl)-1-pyrazole and 1-methyl-4-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-5-yl)-1H-pyrazole (170 mg, 0.7 mmol) from Step 2 of this Examplewere stirred in a 1:1 mixture of TFA and CH2Cl2 (5 mL) for 15 h. The mixture was then concentrated under reducedpressure to afford 4-(1H-imidazol-4-yl)-1-methyl-1H-pyrazole (248 mg) as an oil and was used in the next step withoutfurther purification. LCMS (ESI) m/z 149 (M+H)+.
According to the analysis of related databases, 2302-25-2, the application of this compound in the production field has become more and more popular.
Reference:
Patent; Ambit Biosciences Corporation; HADD, Michael J.; HOCKER, Michael D.; HOLLADAY, Mark W.; LIU, Gang; ROWBOTTOM, Martin W.; XU, Shimin; (299 pag.)EP2766359; (2016); B1;,
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem