5,6,7,4'-Tetramethoxyflavone → Benzaldehyde, 4-(phenylmethoxy)-

HRID 1095271Notes

Reaction equation

HRID 1095271 reaction equation
C[O:2]C1C=CC(C2[O:8][C:9]3[C:14]([C:15](=[O:17])[CH:16]=2)=[C:13]([O:18][CH3:19])[C:12]([O:20][CH3:21])=[C:11]([O:22][CH3:23])[CH:10]=3)=CC=1.OC1C(C(=O)C=[CH:35][C:36]2[CH:41]=[CH:40][C:39]([O:42][CH2:43][C:44]3[CH:49]=[CH:48][CH:47]=[CH:46][CH:45]=3)=[CH:38][CH:37]=2)=C(OC)C(OC)=C(OC)C=1>>[OH:8][C:9]1[C:14]([C:15](=[O:17])[CH3:16])=[C:13]([O:18][CH3:19])[C:12]([O:20][CH3:21])=[C:11]([O:22][CH3:23])[CH:10]=1.[CH2:43]([O:42][C:39]1[CH:40]=[CH:41][C:36]([CH:35]=[O:2])=[CH:37][CH:38]=1)[C:44]1[CH:49]=[CH:48][CH:47]=[CH:46][CH:45]=1

Participants

4

Reactant 2

HCID 961185,6,7,4'-TetramethoxyflavoneHCID 907301966-Hydroxy-1-(4-benzyloxycinnamoyl)-2,3,4-trimethoxybenzene

Product 2

HCID 78109Benzaldehyde, 4-(phenylmethoxy)-HCID 98993751-(6-Hydroxy-2,3,4-trimethoxyphenyl)ethan-1-one

Procedure

Similar to the preparation of 1c, 1e (4′-benzyloxy-5,6,7-trimethoxyflavone) was prepared from 6-hydroxy-1-(4-benzyloxycinnamoyl)-2,3,4-trimethoxybenzene (6b), which, in turn, was obtained from the reaction of the acetophenone 5 and 4-benzyloxybenzaldehyde. A solution of 1e (500 mg, 1.20 mmol) in 48% HBr (5 mL) and glacial acetic acid (10 mL) was refluxed for 2 h. Then, the reaction mixture was poured onto crushed ice (ca. 100 g). The resulting precipitate was filtered and washed with water. Recrystallization from ethanol furnished compound 1f (305 mg, 85%). 1H NMR (DMSO, 200 M Hz) δ 12.63 (br s, 1H), 10.30 (br s, 1H), 8.70 (br s, 1H), 7.93 (d, J=8.8 Hz, 2H), 6.92 (d, J=8.8 Hz, 2H), 6.88 (s 1H), 6.78 (s 1H), 3.90 (s, 3H); 13C NMR (DMSO, 50 M Hz) δ 182.2 (s), 163.8 (s), 161.1 (s), 154.3 (s), 149.6 (s), 146.2 (s), 129.9 (s), 128.4 (d, 2C), 121.4 (s), 116.0 (d, 2C), 105.0 (s), 102.5 (d), 91.1 (d), 56.3 (q). The stereochemistry of compound 1f was confirmed by cosy and nosy experiments.

Sources & evidence

ORD record
ord-d60875e771e84194967a0e540512500c
Source dataset
uspto-grants-2012_03
Patent number
US08138165B2

Reaction notes

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