PURPOSE: To obtain the title compound useful as an intermediate for α-aryl-α- aminoacetic acids (semisynthetic penicillin modifier) in high yield, from a speific aryl compound and allantoin which are safe and industrially available at low prices.
CONSTITUTION: An aryl compound, preferably an unsubstituted phenol, of formula I: (R1 is OH or lower alkoxy group, whose p- or o-position or both are not substituted; R2 and R3 are H, OH, lower alkoxy, lower alkyl, halogen, acylated amino, or nitro groups) is reacted with allantoin of formula II in an acidic aqueous medium, preferably aqueous hydrochloric or sulfuric acid, more preferably with a concentration of 5W25%, at 50°C to reflux temperature to give an 5-arylhydantoin of formula III. The compound of formula II can be obtained by reacting glyoxylic acid with dichloroacetic acid and urea, and used as a raw material described above without isolaton.
| WO/2013/122953 | IMIDAZOLIDINE-2,4-DIONE DERIVATIVES AS N-FORMYL PEPTIDE RECEPTOR 2 MODULATORS |
| JP2023530708 | thyroid mimetic |
KAKIZAKI FUSAYOSHI
IZAWA KUNISUKE
