Phosphorus oxychloride → 4-Chloro-6,7-dimethoxyquinazoline

HRID 429152Notes

Reaction equation

HRID 429152 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:12]=1[O:13][CH3:14])[N:9]=[CH:8][NH:7][C:6]2=O.O=P(Cl)(Cl)[Cl:18]>>[Cl:18][C:6]1[C:5]2[C:10](=[CH:11][C:12]([O:13][CH3:14])=[C:3]([O:2][CH3:1])[CH:4]=2)[N:9]=[CH:8][N:7]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 1354950166,7-Dimethoxy-3H-quinazolin-4-one

Product 1

HCID 27693644-Chloro-6,7-dimethoxyquinazoline

Procedure

Specifically, 4,5-dimethoxy-2-nitrobenzoic acid (compound 1) was treated with thionyl chloride to form acid chloride, followed by reacting with ammonia to yield 4,5-dimethoxy-2-nitrobenzamide (compound 2). Compound 2 was reduced with sodium borohydride in the presence of catalytic amounts of copper sulphate to give 4,5-dimethoxy-2-aminobenzamide (compound 3), which was directly refluxed with formic acid to yield 6,7-dimethoxyquinazoline-4(3H)-one (compound 4). Compound 4 was refluxed with phosphorus oxytrichloride to give 4-chloro-6,7-dimethoxyquinazoline (compound 5) in good yield.

Sources & evidence

ORD record
ord-d1e213c1997f485baf0aff4073ec2449
Source dataset
uspto-grants-2001_11
Patent number
US06316454B1

Reaction notes

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