Dichloromethane → 6-nitro-2,2-dimethyl-3-bromomethyl-4-(2-oxo-1,2-dihydropyridin-1-yl)-2H-1-benzopyran

HRID 1655377Notes

Reaction equation

[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][C:11]([CH3:14])([CH3:13])[C:10]([CH3:15])=[C:9]([N:16]3[CH:21]=[CH:20][CH:19]=[CH:18][C:17]3=[O:22])[C:8]=2[CH:23]=1)([O-:3])=[O:2].[Br:24]N1C(=O)CCC1=O.ClCCl>C(Cl)(Cl)(Cl)Cl.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][C:11]([CH3:14])([CH3:13])[C:10]([CH2:15][Br:24])=[C:9]([N:16]3[CH:21]=[CH:20][CH:19]=[CH:18][C:17]3=[O:22])[C:8]=2[CH:23]=1)([O-:3])=[O:2]

Participants

Conditions

Temperature: 60 °C

Procedure

A suspension of 6-nitro-2,2,3-trimethyl-4-(2-oxo-1,2-dihydropyridin-1-yl)-2H-1-benzopyran (1.62 g, 0.0052 mol) in carbon tetrachloride (10 ml) containing benzoyl peroxide (20 mg) was heated to 60° C. N-bromosuccinimide (0.92 g, 0.0052 mol) was added and the mixture heated at reflux for seventeen hours. The cooled solution was treated with dichloromethane and aqueous ferrous sulfate solution, the organic phase was separated and evaporated under reduced pressure. The residue was chromatographed on silica gel, eluting with dichloromethane/acetone (92.5/7.5). The product was washed with diethyl ether/pentane to give 1.49 g of 6-nitro-2,2-dimethyl-3-bromomethyl-4-(2-oxo-1,2-dihydropyridin-1-yl)-2H-1-benzopyran, m.p. 221° C.

Workup

temperaturethe mixture heated
temperatureat reflux for seventeen hours
customthe organic phase was separated
customevaporated under reduced pressure
customThe residue was chromatographed on silica gel
washeluting with dichloromethane/acetone (92.5/7.5)
washThe product was washed with diethyl ether/pentane

Sources & evidence

ORD record: ord-4adc20fd40cb49dcb89479b23abac817
Source dataset: uspto-grants-1993_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05250547

Reaction notes

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