Acetic Acid → 6-Hydroxy-2,2-dimethyl-5-nitro-chroman-4-one
反応式
[OH:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7]([CH3:13])([CH3:12])[CH2:6][C:5]2=[O:14].C(O)(=O)C.[N+:19]([O-])([O-:21])=[O:20].[K+].OS(O)(=O)=O>O>[OH:1][C:2]1[C:3]([N+:19]([O-:21])=[O:20])=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7]([CH3:12])([CH3:13])[CH2:6][C:5]2=[O:14]参加物
実験手順
To a 250 mL round bottom flask equipped with a magnetic stir bar was added 3 (810 mg, 4.2 mmol) and 15 mL of glacial acetic acid. The mixture was stirred at room temperature until all of the solid dissolved. To a 25 mL vial was added KNO3 (469 mg, 4.6 mmol) and just enough distilled water to dissolve all the KNO3. The aqueous KNO3 solution was transferred to the reaction flask with a pipet. The reaction flask was lowered into an ice water bath (˜10° C.). Concentrated H2SO4 (1 mL) was added drop-wise. The mixture was stirred until all starting material was consumed, as monitored by TLC analysis. Ethyl acetate (20 mL) was added, and the biphasic mixture was transferred into a 500 mL separatory funnel. Saturated aqueous Na2CO3 was added cautiously until the aqueous layer was pH˜7. The aqueous phase was extracted in ethyl acetate (3×20 mL), the combined organic phases were washed with brine (1×50 mL), dried over MgSO4, filtered, concentrated and dried under high vacuum. The dry crude product was passed through a silica gel column using 25:1 CH2Cl/EtOAc as eluent (Rf=0.3). The product gives off a red color on an analytical silica gel plate illuminated with a shortwave UV lamp. The fractions containing the pure product were transferred to a pre-weighed flask, the solvent was evaporated and the concentrate was dried under high vacuum. The reaction furnished 715 mg (72%) of 4 as a yellow solid. 1H NMR (300 MHZ, CDCl3): δ 7.70 (bs, 1H), 7.21 (d, J=9 Hz, 1H), 7.04 (d, J=9 Hz, 1H), 2.76 (s, 2H), 1.46 (s, 6H). 13C NMR (75.5 MHZ, CDCl3): δ 188.9, 154.4, 145.0, 126.4, 124.7(2), 113.1, 80.6, 49.0, 26.4; HRMS (EI+): calculated for C11H11NO5[M+] m/z 237.0637, found 237.0633.
後処理
- customTo a 250 mL round bottom flask equipped with a magnetic stir bar
- dissolutiondissolved
- customThe reaction flask was lowered into an ice water bath
- custom(˜10° C.)
- stirringThe mixture was stirred until all starting material
- customwas consumed
- additionEthyl acetate (20 mL) was added
- customthe biphasic mixture was transferred into a 500 mL separatory funnel
- additionSaturated aqueous Na2CO3 was added cautiously until the aqueous layer
- extractionThe aqueous phase was extracted in ethyl acetate (3×20 mL)
- washthe combined organic phases were washed with brine (1×50 mL)
- dry with materialdried over MgSO4
- filtrationfiltered
- concentrationconcentrated
- customdried under high vacuum
- customThe dry crude product
- customThe product gives off a red color on an analytical silica gel plate
- customilluminated with a shortwave UV lamp
- additionThe fractions containing the pure product
- customwere transferred to a pre-weighed flask
- customthe solvent was evaporated
- customthe concentrate was dried under high vacuum
出典と根拠
- ORDレコード
- ord-6404ad0aedc64459aa206a820352364e
- 出典データセット
- uspto-grants-2009_10
- 特許番号
- US07598403B2
反応ノート
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