Imidazo(1,2-a)pyrimidine-2-aceticacid synthesis

Yield:57892-73-6 1.5 g

Reaction Conditions:

with sodium hydroxide in methanol; for 4 h;Reflux;

Steps:

Imidazo[1,2-a]pyrimidin-2-yl-acetic acid (1) and imidazo[2,1-b]thiazol-6-yl-acetic acid (2).

General procedure: To solution of the respective crude ethylester (0.02 mol) in 100 ml of methanol 1.1 g (0.028 mol) of NaOHwas added, resulted mixture was refluxed for 4 h and cooled toroom temperature. 12 M hydrochloric acid was added dropwise(~2.3 ml, 0.028 mol), the mixture was concentrated under reducedpressure and the residue was treated with 30 ml of diethyl ether.The solid was filtered by suction and washed with 15 ml portions ofdiethyl ether (until the filtrates became colorless). The resultedsolid still containing sodium chloride was dried under reducedpressure, dissolved in about 100 ml of boiling water, decolorizedwith activated charcoal and concentrated to 25e30 ml. The solutionwas left for 24 h at room temperature, the crystallized solid wasfiltered by suction and washed with cold water (3 5 ml) andacetone (2 25 ml). That gave 1.5 g (43%) of imidazo[1,2-a]pyrimidin-2-yl-acetic acid (1) as beige powder and 1.5 g (41%) ofimidazo[2,1-b]thiazol-6-yl-acetic acid (2) as the white tiny needles.

References:

Dylong, Agnieszka;Goldeman, Waldemar;Sowa, Micha?;?lepokura, Katarzyna;Drozdzewski, Piotr;Matczak-Jon, Ewa [Journal of Molecular Structure,2016,vol. 1117,p. 153 - 163]