Sodium Dithionite → N4-(3-Ethynylphenyl)quinazoline-4,6-diamine

HRID 1288860Notes

Reaction equation

HRID 1288860 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]=1

Participants

4

Reactant 2

HCID 24489Sodium DithioniteHCID 18925019(3-Ethynylphenyl)-(6-nitroquinazolin-4-yl)-amine Hydrochloride

Product 1

HCID 11492625N4-(3-Ethynylphenyl)quinazoline-4,6-diamine

Reagents, catalysts & solvents 1

HCID 284Formic AcidSolvent

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.

Workup

  1. customAfter 2 hours the mixture was quenched with 120 mL of water
  2. filtrationfiltered
  3. customThe filtrate was evaporated in vacuo to a residue which
  4. dissolutionwas dissolved in 100 mL of 1:1 methanol
  5. filtrationchloroform, filtered
  6. customevaporated in vacuo to a second residue
  7. customThis was triturated with 200 mL of 5% sodium bicarbonate for 30 minutes
  8. filtrationfiltered
  9. washwashed with water
  10. customdried in vacuo for 16 hours
  11. washFlash chromatography on silica gel eluted with ethyl acetate afforded pure (6-aminoquinazolin-4-yl)-(3-ethynylphenyl)-amine

Sources & evidence

ORD record
ord-29e0faac2ea74826ae12e8b531ae78ef
Source dataset
uspto-grants-1998_05
Patent number
US05747498

Reaction notes

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