Lawesson's reagent → Tert-butyl 8-chloro-3-phenyl[1,2,4]triazolo[4,3-a]pyridine-6-carboxylate

HRID 592298Notes

Reaction equation

[C:1]([NH:9][NH:10][C:11]1[C:23]([Cl:24])=[CH:22][C:14]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])=[CH:13][N:12]=1)(=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=S)=CC=1>C1(C)C=CC=CC=1>[Cl:24][C:23]1[C:11]2[N:12]([C:1]([C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=3)=[N:9][N:10]=2)[CH:13]=[C:14]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[CH:22]=1

Participants

Conditions

Temperature: 80 °C

Procedure

To a solution of tert-butyl 6-(2-benzoylhydrazino)-5-chloronicotinate (3.3 g, 9.49 mmol) in toluene (40 mL) was added Lawesson's reagent (1.92 g, 4.74 mmol). The mixture was stirred at 80° C. After 2 h, the mixture was concentrated. Saturated aqueous sodium bicarbonate was added and the mixture was extracted with ethyl acetate (3×). The combined organic layer was washed with brine, dried over sodium sulfate, filtered and concentrated. Purification by silica gel chromatography (100% dichloromethane→60% dichloromethane/ethyl acetate) gave the title compound (1.42 g): LC-MS [M+1]=330.1.

Workup

concentrationthe mixture was concentrated
additionSaturated aqueous sodium bicarbonate was added
extractionthe mixture was extracted with ethyl acetate (3×)
washThe combined organic layer was washed with brine
dry with materialdried over sodium sulfate
filtrationfiltered
concentrationconcentrated
customPurification by silica gel chromatography (100% dichloromethane→60% dichloromethane/ethyl acetate)

Sources & evidence

ORD record: ord-7376f5f9e5c9492fb53b9f781eaafc7e
Source dataset: uspto-grants-2016_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09238647B2

Reaction notes

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