Sodium Hydroxide → 5-Hydroxy-3-phenyl-5-(trifluoromethyl)-4,5-dihydroisoxazole

Reaction equation

[C:1]([CH2:9][C:10]([C:12]([F:15])([F:14])[F:13])=O)(=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Cl.[NH2:17][OH:18].[OH-:19].[Na+]>>[C:2]1([C:1]2[CH2:9][C:10]([OH:19])([C:12]([F:13])([F:14])[F:15])[O:18][N:17]=2)[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

Reactant 3

HCID 14798Sodium Hydroxide

HCID 675894,4,4-Trifluoro-1-phenyl-1,3-butanedione

HCID 443297Hydroxyamine hydrochloride

Product 1

HCID 28809765-Hydroxy-3-phenyl-5-(trifluoromethyl)-4,5-dihydroisoxazoleYield 91.5%

Procedure

Prepared according to J. Org. Chem., 1995, 60, 3907. A solution of benzoyltrifluoroacetone (21 g, 97 mmol) was added dropwise over 1 h, at 20-30° C., to a solution of hydroxylamine HCl (6.82 g, 98 mmol) containing sodium hydroxide (2 N, 51 mL, 102 mmol) and the resulting mixture heated under reflux for 45 min. After cooling to room temperature, the mixture was poured into ice-water (500 mL), the precipitate was filtered off, washed with water and dried under vacuum to afford the title compound (20.51 g, 91%) which was obtained as a white solid. MS: m/e=230.2 [M−H]−.