Phosphoric Acid → 5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-amine

HRID 1969594Notes

Reaction equation

[S:1]([N:11]1[C:15]2=[N:16][CH:17]=[C:18]([NH:20]C(=O)OC(C)(C)C)[N:19]=[C:14]2[CH:13]=[CH:12]1)([C:4]1[CH:10]=[CH:9][C:7]([CH3:8])=[CH:6][CH:5]=1)(=[O:3])=[O:2].OP(O)(O)=O.[O-]P([O-])([O-])=O.[K+].[K+].[K+]>C1COCC1.O>[S:1]([N:11]1[C:15]2=[N:16][CH:17]=[C:18]([NH2:20])[N:19]=[C:14]2[CH:13]=[CH:12]1)([C:4]1[CH:5]=[CH:6][C:7]([CH3:8])=[CH:9][CH:10]=1)(=[O:2])=[O:3]

Participants

Conditions

Temperature: 65 °C

Procedure

To a solution of tert-butyl 5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-ylcarbamate (12.35 g, 31.8 mmol, Example #3 Step E) in THF (35 mL) was added H3PO4 (20.16 mL, 350 mmol). The reaction mixture was heated to about 65° C. After about 90 min, the reaction mixture was cooled to about 0° C. and a solution of K3PO4 (29.0 mL, 350 mmol) in water (100 mL) was added. A white precipitate was removed by filtration. The organic layer was separated, dried over anhydrous MgSO4, and concd in vacuo to provide crude 5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-amine (8.58 g, 94%) as a tan solid: LC/MS (Table 1, Method a) Rt=1.85 min; MS m/z: 289 (M+H)+.

Workup

temperaturethe reaction mixture was cooled to about 0° C.
customA white precipitate was removed by filtration
customThe organic layer was separated
dry with materialdried over anhydrous MgSO4, and concd in vacuo

Sources & evidence

ORD record: ord-5af3242e3f8a4bb08f2a172b5d830073
Source dataset: uspto-grants-2013_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08426411B2

Reaction notes

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