Hydrochloric Acid → 6-Carbomethoxy-2'-nitro-flavanone

HRID 2083016

Reaction equation

HRID 2083016 reaction equation
[C:1]([C:4]1[CH:5]=[C:6]([CH:12]=[CH:13][C:14]=1[OH:15])[C:7]([O:9][CH2:10]C)=[O:8])(=[O:3])[CH3:2].[N+:16]([C:19]1[CH:26]=[CH:25][CH:24]=[CH:23][C:20]=1[CH:21]=O)([O-:18])=[O:17].Cl>C(O)C.N1CCCCC1.O>[C:7]([C:6]1[CH:5]=[C:4]2[C:14](=[CH:13][CH:12]=1)[O:15][CH:21]([C:20]1[CH:23]=[CH:24][CH:25]=[CH:26][C:19]=1[N+:16]([O-:18])=[O:17])[CH2:2][C:1]2=[O:3])([O:9][CH3:10])=[O:8]

Participants

7

Reactant 3

HCID 313Hydrochloric AcidHCID 111012-NitrobenzaldehydeHCID 12631990Ethyl 3-acetyl-4-hydroxybenzoate

Product 1

HCID 213250586-Carbomethoxy-2'-nitro-flavanone

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 962WaterSolventHCID 8082PiperidineSolvent

Procedure

A mixture consisting of ethyl 3-acetyl-4-hydroxy-benzoate (6 g) and 2-nitro-benzaldehyde (5 g) dissolved in ethanol (100 ml and piperidine (100 ml) was kept at reflux temperature for 24 hours. The mixture was then cooled, diluted in water (800 ml), acidified with hydrochloric acid, extracted with ethylacetate, washed with water and evaporated to dryness to obtain as raw product, 6-carbomethoxy-2'-nitro-flavanone. This product (6.8 g) was dissolved in chloroform (40 ml) and treated with a solution of benzoyl peroxide (0.15 g) and N-bromosuccinimide (3.8 g) dissolved in chloroform (60 ml). The mixture was kept at reflux temperature for 4 hours, then evaporated to dryness under vacuum at low temperature; then the residue, dissolved in ethanol 95% (150 ml), was treated with sodium hydrate 4 N (25 ml) at room temperature for a night. After acidification with hydrochloric acid and filtration, 6-carboxy-2'-nitro-flavone (3.7 g) was obtained, which was subsequently treated with stannous chloride (20 g) in concentrated hydrochloric acid (15 ml) and glacial acetic acid (15 ml) at reflux temperature for 4 hours. After cooling, dilution with water, neutralisation with ammonium hydrate 28 Be, the precipitate was filtered to give, after crystallisation from dimethylformamide, 6-carboxy-2'-amino-flavone (1.8 g; m.p. > 300° C).

Workup

  1. temperatureat reflux temperature for 24 hours
  2. temperatureThe mixture was then cooled
  3. extractionextracted with ethylacetate
  4. washwashed with water
  5. customevaporated to dryness

Sources & evidence

ORD record
ord-fc001214bac947099cc80eb868cb77cf
Source dataset
uspto-grants-1978_04
Patent number
US04083953

Linked notes

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