N-Acetylimidazolidinone → 1-Acetyl-2(3-isopropyl-1-methyl-5-pyrazolyl)amino-2-imidazoline

Participants

Reaction Steps

5-amino-3-isopropyl-1-methyl pyrazole (described in British Patent 1,057,740) (19.3 g) was dissolved in 180 ml phosphorus oxychloride (POCl3). 1-Acetyl-2-imidazolidinone (J. Chem Soc 1964, 178) (20.1 g) was added. This reaction mixture was stirred at 55° for 40 hr. The solvents were concentrated in vacuum, ice and methylene chloride were added and the mixture neutralized with 25% sodium hydroxide in water. The methylene chloride layer was dried over MgSO4 and then concentrated and the residue crystallized from isopropyl alcohol and ether to give 12.73 g. of product, mp 145°-147° C.

Provenance & Evidence