Hydrochloric Acid → 2-Chloro-6,7-dimethoxyquinazoline

HRID 1274157Notes

Reaction equation

HRID 1274157 reaction equation
[BH4-].[Na+].[Cl:3][C:4]1[N:13]=[C:12](Cl)[C:11]2[C:6](=[CH:7][C:8]([O:17][CH3:18])=[C:9]([O:15][CH3:16])[CH:10]=2)[N:5]=1.Cl.C([O-])(O)=O.[Na+]>CCO.C(Cl)Cl>[Cl:3][C:4]1[N:13]=[CH:12][C:11]2[C:6](=[CH:7][C:8]([O:17][CH3:18])=[C:9]([O:15][CH3:16])[CH:10]=2)[N:5]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 516892Sodium BicarbonateHCID 5203272,4-Dichloro-6,7-dimethoxyquinazolineHCID 4311764Sodium borohydride

Product 1

HCID 18181442-Chloro-6,7-dimethoxyquinazolineYield 37%

Reagents, catalysts & solvents 1

HCID 21584144Dichloromethane ethanolSolvent

Conditions

Temperature
25 °C

Procedure

Sodium borohydride (0.23 g, 6.1 mmole) was added to a solution of 2,4-dichloro-6,7-dimethoxyquinazoline (1.0 g, 4 mmol) in EtOH/CH2Cl2 (40 mL; 1:1; v/v) at 25° C. The mixture was stirred at 25° C. for 12 h then was poured into cold HCl aqueous solution (0.4 M, 200 mL). The resulting mixture was basicified with saturated NaHCO3 (aq) and then extracted with EtOAc (3×100 mL). The combined organic layers were dried (Na2SO4), filtered, and concentrated in vacuo to give a yellowish white solid reside. Purification of the residue by flash column chromatography (gradient elution 20 to 35% EtOAc/hexanes) provided the title compound (0.33 g, 37%): TLC (Rf =0.50; 50% EtOAc/hexanes); 1H NMR (DMSO) δ 9.25 (s, 1H), 7.55 (s, 1H), 7.36 (s, 1H), 3.98 (s, 3H), 3.93 (s, 3H); 3C NMR (CDCl3) δ 159.1, 157.3, 156.1, 150.9, 150.1, 119.4, 105.9, 103.7, 56.6, 56.4; HRMS (FAB) m/z 225.0431 (M+H)+ (C10H9N2O2Cl requires 225.0431); Anal. (C10H9N2O2Cl·3/4H2O·1/4CH3OH) C, H, N.

Workup

  1. extractionextracted with EtOAc (3×100 mL)
  2. dry with materialThe combined organic layers were dried (Na2SO4)
  3. filtrationfiltered
  4. concentrationconcentrated in vacuo
  5. customto give a yellowish white solid reside
  6. customPurification of the residue
  7. washby flash column chromatography (gradient elution 20 to 35% EtOAc/hexanes)

Sources & evidence

ORD record
ord-223f03b4fdcb423082052694b882828c
Source dataset
uspto-grants-2000_12
Patent number
US06156758

Reaction notes

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