Ethanol → HCID 54720025, compound

HRID 1577571Notes

Reaction equation

HRID 1577571 reaction equation
C(O)C.NC1C(=O)C2C(C)=CC(C)=CC=2OC=1.[CH3:18][C:19]1[CH:28]=[C:27]([CH3:29])[CH:26]=[C:25]2[C:20]=1[C:21]([OH:31])=[CH:22][C:23](=[O:30])[O:24]2.[N+:32]([O-])([OH:34])=[O:33]>C(O)(=O)C>[CH3:18][C:19]1[CH:28]=[C:27]([CH3:29])[CH:26]=[C:25]2[C:20]=1[C:21]([OH:31])=[C:22]([N+:32]([O-:34])=[O:33])[C:23](=[O:30])[O:24]2

Participants

6

Reactant 4

HCID 702EthanolHCID 944Nitric AcidHCID 20571107HCID 20571107, compoundHCID 547167374-Hydroxy-5,7-dimethyl-2H-1-benzopyran-2-one

Product 1

HCID 54720025HCID 54720025, compound

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

5,7-Dimethyl-3-methoxyoxalylamino-4-oxo-4H-1-benzopyrane with a melting point of 186°-187° (from ethanol) can be prepared in a manner analogous to that described in Example 1, using 3-amino-5,7-dimethyl-4-oxo-4H-1-benzopyrane as the starting material. The starting material can be obtained, for example, using 5,7-dimethyl-4-hydroxy-coumarin as the starting material, by reacting the latter with nitric acid in acetic acid at 80° to give 5,7-dimethyl-4-hydroxy-3-nitro-coumarin, treating this compound for 24 hours with sodium hydroxide solution and subsequently acidifying, with decarboxylation, to give 4,6-dimethyl-2-hydroxy-β-nitro-acetophenone, analogously to the process described in J. Am. Chem. Soc. 67, 99 (1945), and also reacting the latter compound with the mixed anhydride of formic acid and acetic acid to give 5,7-dimethyl-3-nitro-4-oxo-4H-1-benzopyrane with a melting point of 120°-125° and reducing this compound with sodium dithionite to give 3-amino-5,7-dimethyl-4-oxo-4H-1-benzopyrane (melting point 120°-121°), analogously to the process described in Tetrahedron Letters 1976, 719, and purifying this product via the hydrochloride.

Workup

  1. customat 80°

Sources & evidence

ORD record
ord-eea27ae251434764a1a297863e2a92f1
Source dataset
uspto-grants-1981_09
Patent number
US04288450

Reaction notes

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