Hydrochloric Acid → 4-(3-ethoxy-4-hydroxy-5-nitrophenyl)-6-(1-methyl-1H-pyrazol-3-yl)-5-(thiophen-3-yl)-3,4-dihydropyrimidin-2(1H)-one

Participants

Reaction Steps

A mixture of 1-(1-methyl-1H-pyrazol-3-yl)-2-(thiophen-3-yl)ethanone (Intermediate 58) (750 mg, 3.6 mmol), 4-hydroxy-3-methoxy-5-nitrobenzaldehyde (782 mg, 3.7 mmol), urea (666 mg, 11.1 mmol) and conc. HCl (0.2 mL) in EtOH (10 mL) was refluxed overnight. The mixture was concentrated under reduced pressure to dryness and purified by prep-HPLC (0.1% TFA as additive) to give Compound 119 (1.3 g, yield 81%). 1H NMR and MS (ESI) characterization included for the individual enantiomers, see Compound 149 and Compound 150.

Provenance & Evidence