Nitric Acid → 6-nitro-2,2,3-trimethyl-3,4-dihydro-2H-1-benzopyran-4-one

HRID 2399301Notes

Reaction equation

[CH3:1][C:2]1([CH3:14])[CH:7]([CH3:8])[C:6](=[O:9])[C:5]2[CH:10]=[CH:11][CH:12]=[CH:13][C:4]=2[O:3]1.[N+:15]([O-])([OH:17])=[O:16]>S(=O)(=O)(O)O>[N+:15]([C:11]1[CH:12]=[CH:13][C:4]2[O:3][C:2]([CH3:1])([CH3:14])[CH:7]([CH3:8])[C:6](=[O:9])[C:5]=2[CH:10]=1)([O-:17])=[O:16]

Participants

Conditions

Temperature: 5 °C

Procedure

To a solution of 2,2,3-trimethyl-3,4-dihydro-2H-1-benzopyran-4-one (81 g, 0.426 mol) in concentrated sulfuric acid (695 ml) at 0° C. was added a solution containing concentrated sulfuric acid (30 ml) and nitric acid (65%, 175 ml) while maintaining the temperature below 5° C. After stirring for three hours at 5° C., the mixture was added to ice/water and the crude product recovered by filtration. This product was dried and washed with diisopropyl ether to give 44 g of 6-nitro-2,2,3-trimethyl-3,4-dihydro-2H-1-benzopyran-4-one, m.p. 78° C.

Workup

temperaturewhile maintaining the temperature below 5° C
filtrationthe crude product recovered by filtration
customThis product was dried
washwashed with diisopropyl ether

Sources & evidence

ORD record: ord-09e277c451aa4a15b8cbcf27254acc51
Source dataset: uspto-grants-1995_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05447943

Reaction notes

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