(E)-Methyl 2-(2-chloro-6-nitrophenyl)-3-hydroxybut-2-enoate → methyl 4-chloro-2-methyl-1H-indole-3-carboxylate

HRID 453853Notes

Reaction equation

[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([N+:8]([O-])=O)[C:3]=1/[C:11](=[C:16](\O)/[CH3:17])/[C:12]([O:14][CH3:15])=[O:13]>C(O)(=O)C.O.C(Cl)Cl.CO>[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]2[C:3]=1[C:11]([C:12]([O:14][CH3:15])=[O:13])=[C:16]([CH3:17])[NH:8]2

Participants

Conditions

Temperature: 90 °C

Procedure

(E)-Methyl 2-(2-chloro-6-nitrophenyl)-3-hydroxybut-2-enoate (14.76 mmol, 1.0 equiv.) was dissolved in acetic acid (96 ml), and a solution of TiCl3 (20%-w/w in 2 N HCl, 71.6 ml) was added, with stirring. The mixture was then heated for 5-10 min at 90° C. The reaction mixture was cooled with an ice bath and diluted with water and DCM/methanol (9:1, 100 ml). The phases were separated and the organic phase was washed with water and sat. NaCl solution. Drying over Na2SO4 was then carried out, followed by concentration under reduced pressure. The product was crystallized from hexane. Yield: 91%

Workup

temperatureThe reaction mixture was cooled with an ice bath
customThe phases were separated
washthe organic phase was washed with water and sat. NaCl solution
dry with materialDrying over Na2SO4
concentrationfollowed by concentration under reduced pressure
customThe product was crystallized from hexane

Sources & evidence

ORD record: ord-b221d243f2524303bc50d79c785b5aca
Source dataset: uspto-grants-2013_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08492559B2

Reaction notes

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