Acetic Acid → HCID 59598355, compound

Participants

Reaction Steps

thyl isonicotinoylacetate (3.01 g, 16 mmol) and 1-methyl-2-phenylhydrazine (2.03 g, 17 mmol) were suspended in water (50 ml) and glacial acetic acid (1.35 ml, 23 mmol) was added. The flask was fitted with a reflux condenser and placed in a preheated oil bath (115 C) and stirred. After 4 hours, the reaction cooled to room temperature and extracted with EtOAc (2×100 ml; 50 ml), 10:1 DCM/MeOH (110 ml), and EtOAc again. The organic phases were combined, dried over sodium sulfate, filtered, and concentrated. The crude material was purified on silica gel (DCM->20:1->10:1 DCM/MeOH->10:1->4:1 DCM/2 N ammonia in MeOH). Fractions with product collected, concentrated, and repurified on silica gel using DCM->20:1 DCM/MeOH->5:1 DCM/2 N ammonia in MeOH). The fractions with product were collected and concentrated to give 1-methyl-2-phenyl-5-(pyridin-4-yl)-1,2-dihydropyrazol-3-one (3.31 g, 70% purity, 9.2 mmol, 59%). MS (ESI pos. ion) m/z: 252 (MH+). Calc'd exact mass for C15H13N3O: 251.

Provenance & Evidence