Potassium Carbonate → 7-Methoxy-3-(4-methoxyphenyl)thiochroman-4-one

HRID 1859337Notes

Reaction equation

[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([CH:9]([CH2:13][S:14][C:15]2[CH:20]=[CH:19][CH:18]=[C:17]([O:21][CH3:22])[CH:16]=2)[C:10]([OH:12])=O)=[CH:5][CH:4]=1.C(=O)([O-])[O-].[K+].[K+].P(Cl)(Cl)(Cl)=O>C(#N)C>[CH3:22][O:21][C:17]1[CH:16]=[C:15]2[C:20]([C:10](=[O:12])[CH:9]([C:6]3[CH:5]=[CH:4][C:3]([O:2][CH3:1])=[CH:8][CH:7]=3)[CH2:13][S:14]2)=[CH:19][CH:18]=1

Participants

Conditions

Temperature: 60 °C

Procedure

To acetonitrile solution (120 ml) of 2-(4-methoxyphenyl)-3-(3-methoxyphenylthio)propionic acid (4) (12.8 g, 40.3 mmol) obtained above was added potassium carbonate (1.59 g, 11.5 mmol) and phosphorus oxychloride (18.7 ml, 200 mmol) at 0° C. and then stirred for 18 hours at 60° C. The reaction solution was quenched with ice-water and extracted with ether. The organic layer was washed with saturated saline, dried over anhydrous magnesium sulfate and then distilled under reduced pressure to remove the solvent. The obtained crude product was washed with ether to obtain 6.8 g of the first crop of 7-methoxy-3-(4-methoxyphenyl)thiochroman-4-one (5). Further, the filtrate was concentrated and the residue was then purified with silica gel column chromatography (ethyl acetate:hexane=1:3) to obtain 1.0 g of the second crop of 7-methoxy-3-(4-methoxyphenyl)thiochroman-4-one (5) (total yield: 7.8 g, 65%). NMR data of the compound (5) was identical to that described in Example 25.

Workup

customThe reaction solution was quenched with ice-water
extractionextracted with ether
washThe organic layer was washed with saturated saline
dry with materialdried over anhydrous magnesium sulfate
distillationdistilled under reduced pressure
customto remove the solvent
customThe obtained crude product
washwas washed with ether

Sources & evidence

ORD record: ord-0ad73b2939144917845e6748e62f173b
Source dataset: uspto-grants-2000_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06153768

Reaction notes

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