Reference of 1904-31-0, These common heterocyclic compound, 1904-31-0, name is 1-Methyl-1H-pyrazol-3-amine, its 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.
To a stirred suspension of 1-methyl-1H-pyrazol-3-amine 76a (0.5 g, 5.1 mmol) in toluene (20 mL) in an round bottom flask fitted with Dean-Stark apparatus was charged with hexane-2,5-dione (0.70 g, 6.1 mmol) followed by p-toluene sulfonic acid (0.097 g, 0.51 mmol) and the reaction mixture was heated at 115°C for about 6 h. The reaction mixture was cooled to room temperature. Reaction mass was concentrated fully under reduced pressure, residue obtained was dissolved in DCM, given water wash followed by brine wash, dried over Na2504 and concentrated under redcued pressure to obtain 3-(2,5-dimethyl-1H-pyrrol-1-yl)-1-methyl-1H-pyrazole 76b (0.55 g, 55percent yield) as green oil. 1HNMR (400 MHz, CDC13): 6 7.39 (d, 111), 6.15 (s, 1H), 5.85 (s, 2H), 3.92 (s, 3H), 2.10 (s, 6H), MS: 176.11 (M+H).
The synthetic route of 1904-31-0 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; JUBILANT BIOSYS LIMITED; VENKATESHAPPA, Chandregowda; SIVANANDHAN, Dhanalakshmi; BAKTHAVATCHALAM, Rajagopal; KETHIRI, Raghava Reddy; VISWANADHAN, Vellarkad Narayana; GIRI, Sanjeev; WO2015/25197; (2015); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics