Sodium Thiosulfate → 3-Fluoro-5-iodo-4-methylbenzoic acid
Reaction equation
[F:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[CH3:11])[C:5]([OH:7])=[O:6].[I:12]C1CC(=O)NC1=O.S([O-])([O-])(=O)=S.[Na+].[Na+]>FC(F)(F)S(O)(=O)=O>[F:1][C:2]1[CH:3]=[C:4]([CH:8]=[C:9]([I:12])[C:10]=1[CH3:11])[C:5]([OH:7])=[O:6]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -20 °C
Procedure
A solution of 3-fluoro-4-methylbenzoic acid (149.7 g) in trifluoromethanesulphonic acid (1050 ml) at −22° C. under nitrogen was treated portionwise over 1.25 h with iodosuccinimide (203.5 g). The mixture was stirred at −20° C. for and further portions of iodosuccinimide were added after 2.5 h (46.5 g) and 20.5 h (30 g). The mixture was stirred at −20° C. for a further 24 h then added slowly to a mixture of aqueous sodium thiosulphate (10%, 1.5 L) and ice (3 kg). The resultant precipitate was collected by filtration and stirred with ethyl acetate (5 L) and aqueous sodium thiosulphate (10%, 1.5 L). The organic phase was dried (MgSO4) and concentrated to ˜1.5 L then left overnight. The precipitate was collected by filtration and further material was obtained through concentration of the filtrate to give the title compound as a white solid (133.9 g).
Workup
- additionwere added after 2.5 h (46.5 g) and 20.5 h (30 g)
- filtrationThe resultant precipitate was collected by filtration
- stirringstirred with ethyl acetate (5 L) and aqueous sodium thiosulphate (10%, 1.5 L)
- dry with materialThe organic phase was dried (MgSO4)
- concentrationconcentrated to ˜1.5 L
- waitthen left overnight
- filtrationThe precipitate was collected by filtration
- customfurther material was obtained through concentration of the filtrate
Sources & evidence
- ORD record
- ord-772c73d3b9924d6c832e98a67d2013a1
- Source dataset
- uspto-grants-2010_03
- Patent number
- US07687532B2
Reaction notes
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