p-Toluenesulfonic acid monohydrate → (R)-4-(3,4-dichlorobenzenesulfonyl)-3-(prop-2-ynyl)-3,4-dihydropyrazin-2(1H)-one

HRID 1432005Notes

Reaction equation

[Cl:1][C:2]1[CH:3]=[C:4]([S:9]([NH:12][C@H:13]([CH2:23][C:24]#[CH:25])[C:14]([NH:16][CH2:17][CH:18](OC)OC)=[O:15])(=[O:11])=[O:10])[CH:5]=[CH:6][C:7]=1[Cl:8].CC1C=CC(S(O)(=O)=O)=CC=1.O>O1CCOCC1>[Cl:1][C:2]1[CH:3]=[C:4]([S:9]([N:12]2[CH:18]=[CH:17][NH:16][C:14](=[O:15])[C@H:13]2[CH2:23][C:24]#[CH:25])(=[O:11])=[O:10])[CH:5]=[CH:6][C:7]=1[Cl:8]

Participants

Conditions

Temperature: 60 °C

Procedure

A solution of (R)-2-(3,4-dichlorobenzenesulfonamido)-N-(2,2-dimethoxyethyl)pent-4-ynamide (36.7 g, 89.6 mmol) in 500 mL p-dioxane was treated with TsOH.H2O (5.11 g, 26.9 mmol). The reaction was heated to 60° C. for 7 h and then at 80° C. for 19 h. The mixture was cooled to room temperature and concentrated under reduced pressure. The residue was diluted with 400 mL EtOAc stirred with 400 mL 5% NaHCO3. The resulting precipitate was filtered and washed with H2O. The solid was suspended in hot EtOH and cooled to rt. The solid was collected by filtration, washed with EtOH and dried in vacuo to yield the title compound.

Workup

temperatureThe mixture was cooled to room temperature
concentrationconcentrated under reduced pressure
additionThe residue was diluted with 400 mL EtOAc
filtrationThe resulting precipitate was filtered
washwashed with H2O
temperaturecooled to rt
filtrationThe solid was collected by filtration
washwashed with EtOH
customdried in vacuo

Sources & evidence

ORD record: ord-59642001d96a401590d92d9426a3b46d
Source dataset: uspto-grants-2009_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07612060B2

Reaction notes

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