Some common heterocyclic compound, 2075-45-8, name is 4-Bromo-1H-pyrazole, molecular formula is C3H3BrN2, 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. HPLC of Formula: C3H3BrN2
A 500 mL Schlenk flask backfilled with N2was added 4-bromo-1H-pyrazole (10.0g, 68.0 mmol) and dry THF (250 mL). The resulting solution was cooled to 0 C understirring before 60% NaH dispersion (3.3 g, 81.6 mmol) was added slowly. Once H2evolution had ceased, trityl chloride (20.9 g, 74.8 mmol) was added slowly, andthe resulting mixture was stirred overnight at RT before quenching with H2O(5 mL) and drying in vacuo.Theresulting residue was triturated in dichloromethane (5 mL) and methanol (200mL) for 2 hours.The resulting suspension wasfiltered and dried overnight at 50C to give4-bromo-1-trityl-1H-pyrazole(26.0g, 66.8 mmol, 98.2%) as a white solid.1HNMR (300 MHz, DMSO-d6)delta = 7.03 – 7.06 (m, 6 H), 7.34 – 7.40 (m, 9 H), 7.51 (s, 1 H), delta 7.76 (s, 1H).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2075-45-8, its application will become more common.
Reference:
Article; Kershaw Cook, Laurence J.; Kearsey, Rachel; Lamb, Jessica V.; Pace, Edward J.; Gould, Jamie A.; Tetrahedron Letters; vol. 57; 8; (2016); p. 895 – 898;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics