m-Chloroperbenzoic acid → 2H-Pyrano(2,3-b)pyridine, 2-(3,4-dichlorophenyl)-3,4-dihydro-6-(methylsulfinyl)-

HRID 280200Notes

Reaction equation

[Cl:1][C:2]1[CH:3]=[C:4]([CH:9]2[O:20][C:13]3=[N:14][CH:15]=[C:16]([S:18][CH3:19])[CH:17]=[C:12]3[CH2:11][CH2:10]2)[CH:5]=[CH:6][C:7]=1[Cl:8].ClC1C=C(C=CC=1)C(OO)=[O:26]>C(Cl)Cl>[Cl:1][C:2]1[CH:3]=[C:4]([CH:9]2[O:20][C:13]3=[N:14][CH:15]=[C:16]([S:18]([CH3:19])=[O:26])[CH:17]=[C:12]3[CH2:11][CH2:10]2)[CH:5]=[CH:6][C:7]=1[Cl:8]

Participants

Conditions

Temperature: -5 °C

Procedure

To a stirred solution of 1.0 g of 2-(3,4-dichlorophenyl)-3,4-dihydro-6-(methylthio)-2H-pyrano[2,3-b]pyridine in 25 ml of methylene chloride at -25° C. there was added dropwise a solution of 0.55 g of 80-85% m-chloroperoxybenzoic acid in 20 ml of methylene chloride over 5-10 minutes while keeping the temperature between -20° and -30° C. A precipitate formed. The mixture was then allowed to warm to -5° C. over 2 hours and then extracted with aqueous saturated sodium bicarbonate solution, aqueous saturated sodium chloride solution, dried over sodium sulfate and concentrated under reduced pressure to leave a pale yellow solid. This was recrystallized from a mixture of ethyl acetate and hexane to give 2-(3,4-dichlorophenyl)-3,4-dihydro-6-(methylsulfinyl)-2H-pyrano[2,3-b]pyridine as a cream-colored solid melting at about 159°-162° C.

Workup

customthe temperature between -20° and -30° C
customA precipitate formed
extractionextracted with aqueous saturated sodium bicarbonate solution, aqueous saturated sodium chloride solution
dry with materialdried over sodium sulfate
concentrationconcentrated under reduced pressure
customto leave a pale yellow solid
customThis was recrystallized from a mixture of ethyl acetate and hexane

Sources & evidence

ORD record: ord-82478400a44a4653986ff8d0fe8f1ed6
Source dataset: uspto-grants-1986_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04588733

Reaction notes

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