Boron tribromide → 1,2-Benzenediol, 5-(2-amino-4-thiazolyl)-3-nitro-, monohydrobromide
Reaction equation
[NH2:1][C:2]1[S:3][CH:4]=[C:5]([C:7]2[CH:12]=[C:11]([N+:13]([O-:15])=[O:14])[C:10]([OH:16])=[C:9]([O:17]C)[CH:8]=2)[N:6]=1.B(Br)(Br)[Br:20]>C(Cl)Cl>[BrH:20].[NH2:1][C:2]1[S:3][CH:4]=[C:5]([C:7]2[CH:8]=[C:9]([OH:17])[C:10]([OH:16])=[C:11]([N+:13]([O-:15])=[O:14])[CH:12]=2)[N:6]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A suspension of 267.3 mg of 4-(2-amino-4-thiazolyl)-2-methoxy-6-nitrophenol in 10 ml of dry methylene chloride is treated at -20° with 1.25 g of boron tribromide. After the addition the mixture is stirred at -20° for a further 1 hour and at room temperature without cooling for 18 hours. The reaction mixture is then evaporated, the residue is treated cautiously with water and stirred at 50° for 30 minutes. After cooling to room temperature the mixture is suction filtered and the crude product is removed by filtration and washed with a small amount of water. There is obtained 5-(2-amino-4-thiazolyl)-3-nitropyrocatechol hydrobromide of m.p. 244°-246° (from methanol).