Sodium Dithionite → N4-(3-Ethynylphenyl)quinazoline-4,6-diamine
Reaction equation
Cl.[C:2]([C:4]1[CH:5]=[C:6]([NH:10][C:11]2[C:20]3[C:15](=[CH:16][CH:17]=[C:18]([N+:21]([O-])=O)[CH:19]=3)[N:14]=[CH:13][N:12]=2)[CH:7]=[CH:8][CH:9]=1)#[CH:3].S(S([O-])=O)([O-])=O.[Na+].[Na+]>C(O)=O>[NH2:21][C:18]1[CH:19]=[C:20]2[C:15](=[CH:16][CH:17]=1)[N:14]=[CH:13][N:12]=[C:11]2[NH:10][C:6]1[CH:7]=[CH:8][CH:9]=[C:4]([C:2]#[CH:3])[CH:5]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
(3-Ethynyl-phenyl)-(6-nitro-quinazolin-4-yl)-amine hydrochloride (500 mg, 1.50 mmol) was dissolved in 10 mL of formic acid and treated portion-wise with sodium dithionite (1.10 g, 6.28 mmol) at room temperature. After 2 hours the mixture was quenched with 120 mL of water and filtered. The filtrate was evaporated in vacuo to a residue which was dissolved in 100 mL of 1:1 methanol:chloroform, filtered and evaporated in vacuo to a second residue. This was triturated with 200 mL of 5% sodium bicarbonate for 30 minutes, filtered, washed with water and dried in vacuo for 16 hours. Flash chromatography on silica gel eluted with ethyl acetate afforded pure (6-aminoquinazolin-4-yl)-(3-ethynylphenyl)-amine; 140 mg (34%); mp 165° C. dec.