Hydrochloric Acid → 2-Hydrazinyl-5-tosyl-5H-pyrrolo[2,3-b]pyrazine

HRID 1854422Notes

Reaction equation

[S:1]([N:11]1[C:15]2=[N:16][CH:17]=[C:18]([NH:20][NH:21]C(OC(C)(C)C)=O)[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].S(N1C2=NC=C(N(C(OC(C)(C)C)=O)N)N=C2C=C1)(C1C=CC(C)=CC=1)(=O)=O.Cl>O1CCOCC1>[NH:20]([C:18]1[N:19]=[C:14]2[CH:13]=[CH:12][N:11]([S:1]([C:4]3[CH:10]=[CH:9][C:7]([CH3:8])=[CH:6][CH:5]=3)(=[O:2])=[O:3])[C:15]2=[N:16][CH:17]=1)[NH2:21]

Participants

Conditions

Temperature: 60 °C

Procedure

To a mixture of tert-butyl 2-(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)hydrazinecarboxylate and tert-butyl 1-(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)hydrazinecarboxylate (18.8 g, 46.6 mmol) in 1,4-dioxane (239 mL) was added HCl (4 M in 1,4-dioxane, 86 mL, 345 mmol). The reaction was heated at about 60° C. for about 1 h and then cooled to about 15-20° C. The solid was collected by vacuum filtration, washed with cold 1,4-dioxane (2×20 mL), and then stirred with a solution of saturated aqueous NaHCO3 and water (1:1, 150 mL). After about 1 h, the effervescence had subsided and the solid was collected by vacuum filtration, washed with ice cold water (3×20 mL), and dried in a vacuum oven to a constant weight to afford 2-hydrazinyl-5-tosyl-5H-pyrrolo[2,3-b]pyrazine as a light yellowish brown solid (8.01 g, 50%): LC/MS (Table 2, Method d) Rt=1.28 min; MS m/z: 304 (M+H)+.

Workup

temperaturecooled to about 15-20° C
filtrationThe solid was collected by vacuum filtration
washwashed with cold 1,4-dioxane (2×20 mL)
filtrationthe solid was collected by vacuum filtration
washwashed with ice cold water (3×20 mL)
customdried in a vacuum oven to a constant weight

Sources & evidence

ORD record: ord-a7f6e3a0ad174ff5a2daa225f81d2ee6
Source dataset: uspto-grants-2015_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08962629B2

Reaction notes

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