Sodium Dithionite → AP-24592

Reaction equation

[CH3:1][N:2]1[CH2:7][CH2:6][N:5]([CH2:8][C:9]2[CH:14]=[CH:13][C:12]([N+:15]([O-])=O)=[CH:11][C:10]=2[C:18]([F:21])([F:20])[F:19])[CH2:4][CH2:3]1.S(S([O-])=O)([O-])=O.[Na+].[Na+]>CC(C)=O.O>[CH3:1][N:2]1[CH2:7][CH2:6][N:5]([CH2:8][C:9]2[CH:14]=[CH:13][C:12]([NH2:15])=[CH:11][C:10]=2[C:18]([F:21])([F:19])[F:20])[CH2:4][CH2:3]1

Participants

Procedure

A suspension of 1-methyl-4-(4-nitro-2-(trifluoromethyl)benzyl)piperazine (1.23 g, 4 mmol) and sodium hydrosulfite (7.0 g, 85% pure from Aldrich, 40 mmol) in acetone and water (1:1, 20 mL) was refluxed for 3 h. Upon cooling, the volatile components (mainly acetone) were removed on rotavap, and the resulting mixture was subjected to filtration. The solid was thoroughly washed with EtOAc. The combined filtrate was extracted with n-BuOH (4×), and the combined organic layer was washed with saturated aq. NaHCO3, dried (Na2SO4), filtered, concentrated, and the resulting residue was purified by silica gel chromatography (eluted with 5% MeOH/DCM, MeOH was pre-saturated with ammonia gas) to provide 0.71 g of product as a pale yellow solid.