Ammonium Hydroxide → Ethyl 2-(3-bromo-6-methyl-2-oxopyrazin-1(2H)-yl)acetate

HRID 1016260Notes

Reaction equation

[CH2:1]([O:3][C:4]([CH2:6][N:7]1[C:12]([CH3:13])=[CH:11][N:10]=[C:9](O)[C:8]1=[O:15])=[O:5])[CH3:2].P(Br)(Br)([Br:18])=O.[OH-].[NH4+]>C(Cl)(Cl)Cl.ClCCl>[Br:18][C:9]1[C:8](=[O:15])[N:7]([CH2:6][C:4]([O:3][CH2:1][CH3:2])=[O:5])[C:12]([CH3:13])=[CH:11][N:10]=1

Participants

Conditions

Temperature: 50 °C

Procedure

A slurry of 1-(ethoxycarbonylmethyl)-3-hydroxy-6-methylpyrazinone (4.24 g, 20 mmol), as prepared in the preceding step, and phosphorous oxybromide (6.3 g, 22 mmol) in chloroform (15 mL) was stirred at 50° C. under nitrogen for 2 hours, then allowed to cool to room temperature overnight. The reaction mixture was diluted with dichloromethane and ice-water, basified with ammonium hydroxide, and extracted with dichloromethane. The combined organic layers were washed with brine, dried over Na2SO4, treated with activated carbon, filtered and concentrated. The solid was collected, washed with 15% ethyl acetate in hexane, and dried under high vacuum to give the title compound as an orange colored solid (5.1 g, 93%). 1H NMR (400 MHz, CDCl3) δ 7.06 (s, 1H), 4.77 (s, 2H), 4.26 (q, 2 H, J=7.1 Hz), 2.24 (s, 3H), 1.31 (t, 3H, J=7.1 Hz).

Workup

temperatureto cool to room temperature overnight
extractionextracted with dichloromethane
washThe combined organic layers were washed with brine
dry with materialdried over Na2SO4
additiontreated with activated carbon
filtrationfiltered
concentrationconcentrated
customThe solid was collected
washwashed with 15% ethyl acetate in hexane
customdried under high vacuum

Sources & evidence

ORD record: ord-3598301550ae497b9ea99e3db5b41215
Source dataset: uspto-grants-2002_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06476016B2

Reaction notes

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