Nitronium → HCID 178504683, compound

HRID 423606Notes

Reaction equation

N([O-])=O.[Na+].[CH3:5][S:6]([C:9]1[CH:14]=[CH:13][C:12]([C:15]2[N:16]=[CH:17][C:18](N)=[N:19][CH:20]=2)=[CH:11][CH:10]=1)(=[O:8])=[O:7].[O:22]=[N+]=O>OS(O)(=O)=O>[CH3:5][S:6]([C:9]1[CH:14]=[CH:13][C:12]([C:15]2[N:16]=[CH:17][C:18]([OH:22])=[N:19][CH:20]=2)=[CH:11][CH:10]=1)(=[O:8])=[O:7]

Participants

Conditions

Temperature: 0 °C

Procedure

NaNO2 (0.20 g, 2.76 mmol) was added in portions to concentrated H2SO4 (1.4 mL) at 0° C. The mixture was heated at 50° C. until all of the NaNO2 had dissolved and the mixture was again cooled to 0° C. A solution of 5-[4-(methylsulfonyl)phenyl]-2-pyrazinamine (0.51 g, 2.05 mmol) in concentrated H2SO4 (4.2 mL) was added dropwise to the nitronium solution. The ice bath was removed, and the mixture was warmed to ambient temperature and stirred for 15 min, then heated to 45° C. for 30 min. The mixture was cooled to ambient temperature and poured into ice water. The pH was adjusted to about 4 with 4N NaOH and the solid was collected, washed with water, and air dried to give 0.415 g (81%) of 5-[4-(methylsulfonyl)phenyl]-2-pyrazinol (and tautomers thereof) as a brown solid. 1H NMR (400 MHz, DMSO-d6): δ 12.77 (bs, 1H), 8.30-8.05 (m, 4H), 7.92 (d, 2H, J=8.6 Hz), 3.21 (s, 3H); LRMS (ESI), m/z 251 (M+H).

Workup

dissolutionhad dissolved
customThe ice bath was removed
temperaturethe mixture was warmed to ambient temperature
temperatureheated to 45° C. for 30 min
temperatureThe mixture was cooled to ambient temperature
additionpoured into ice water
customthe solid was collected
washwashed with water, and air
customdried

Sources & evidence

ORD record: ord-d67b34d8e8ba4077938469a358cfe7f8
Source dataset: uspto-grants-2012_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08101634B2

Reaction notes

Loading…