Trifluoroacetic anhydride → 6-Bromo-2-cyclopropyl-3-methylimidazo[1,2-a]pyrazine

HRID 2203016Notes

Reaction equation

[Br:1][C:2]1[N:3]=[CH:4][C:5](=[N:15]S(C2C=CC(C)=CC=2)(=O)=O)[N:6]([CH:8]([CH3:14])[C:9]([CH:11]2[CH2:13][CH2:12]2)=O)[CH:7]=1.FC(F)(F)C(OC(=O)C(F)(F)F)=O>C1COCC1>[Br:1][C:2]1[N:3]=[CH:4][C:5]2[N:6]([C:8]([CH3:14])=[C:9]([CH:11]3[CH2:13][CH2:12]3)[N:15]=2)[CH:7]=1

Participants

Conditions

Temperature: 60 °C

Procedure

To a solution of N-(5-bromo-1-(1-cyclopropyl-1-oxopropan-2-yl)pyrazin-2(1H)-ylidene)-4-methylbenzenesulfonamide (1.24 g) in THF (10 ml) was added trifluoroacetic anhydride (1.23 g) at 0° C., and the mixture was heated at 60° C. for 3 h. The mixture was partitioned between EtOAc and saturated NaHCO3 solution, and the organic layer was washed with 1 M NaOH and brine successively, dried over MgSO4, concentrated in vacuo, and purified by silica gel column chromatography (hexane/EtOAc) to give the title compound (593 mg) as pale yellow crystals.

Workup

customThe mixture was partitioned between EtOAc and saturated NaHCO3 solution
washthe organic layer was washed with 1 M NaOH and brine successively
dry with materialdried over MgSO4
concentrationconcentrated in vacuo
custompurified by silica gel column chromatography (hexane/EtOAc)

Sources & evidence

ORD record: ord-f8544c1bf2f040de883c953ff768096d
Source dataset: uspto-grants-2016_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09365540B2

Reaction notes

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