3-Bromopropionic acid → 3-(1,3-Benzoxazol-2-ylsulfanyl)propanoic acid

Reaction equation

Br[CH2:2][CH2:3][C:4]([OH:6])=[O:5].[SH:7][C:8]1[O:9][C:10]2[CH:16]=[CH:15][CH:14]=[CH:13][C:11]=2[N:12]=1.[OH-].[K+]>C(O)C>[O:9]1[C:10]2[CH:16]=[CH:15][CH:14]=[CH:13][C:11]=2[N:12]=[C:8]1[S:7][CH2:2][CH2:3][C:4]([OH:6])=[O:5]

Participants

Procedure

Ethanol (EtOH) (35 ml), 3-bromopropanoic acid (1.53 g, 10 mmols) and 2-mercaptobenzoxazole (1.51 g, 10mmols) were added in that order to an aqueous (15 ml) solution of potassium hydroxide (KOH) (1.0 g, 17.8 mmols), and heated under reflux for 3 hours. The reaction mixture was concentrated under reduced pressure, water was added to the resulting residue, and this was made acidic (pH=1) with 1N HCl added thereto. The precipitate formed was taken out through filtration, and crystallized in acetone-ether-hexane to obtain 1.3 g (58%) of 3-(benzoxazol-2-ylthio)propanoic acid as colorless crystals.