Sulfuric Acid → 2-(4-Chloro-2-fluoro-5-hydroxyphenyl)hexahydro-3-thioxo-1H-[1,2,4]triazolo[1,2-a]pyridazin-1-one

HRID 1953986Notes

Reaction equation

S(=O)(=O)(O)O.[Cl:6][C:7]1[C:12]([O:13]C(C)C)=[CH:11][C:10]([N:17]2[C:25](=[O:26])[N:20]3[CH2:21][CH2:22][CH2:23][CH2:24][N:19]3[C:18]2=[S:27])=[C:9]([F:28])[CH:8]=1>C(Cl)Cl>[Cl:6][C:7]1[C:12]([OH:13])=[CH:11][C:10]([N:17]2[C:25](=[O:26])[N:20]3[CH2:21][CH2:22][CH2:23][CH2:24][N:19]3[C:18]2=[S:27])=[C:9]([F:28])[CH:8]=1

Participants

Conditions

Temperature: 0 °C

Procedure

Conc. sulfuric acid (22 ml) was added dropwise to a solution of 2-[4-chloro-2-fluoro-5-(isopropyloxy)phenyl]hexahydro-3-thioxo-1H-[1,2,4]triazolo[1,2-a]pyridazin-1-one (17.2 g) in methylene chloride (120 ml) stirred at 0° C. The mixture was stirred at room temperature for 1 hour and ice-water (200 g) added. The aqueous phase was extracted with methylene chloride and the organic phases combined, dried over sodium sulfate and chromatographed (silica gel, ethyl acetate) to give the product (14.5 g, 96%). 1H NMR (CDCl3, TMS): 1.84(4H, m), 3.82(4H, m), 7.06(1H, d, J=6.5 Hz), 7.58(1H, d, J=8.8 Hz), 10.6(1H, s).

Workup

stirringThe mixture was stirred at room temperature for 1 hour
extractionThe aqueous phase was extracted with methylene chloride
dry with materialdried over sodium sulfate
customchromatographed (silica gel, ethyl acetate)

Sources & evidence

ORD record: ord-01cb2d31b3d9435aae9bd6034aeed38d
Source dataset: uspto-grants-2000_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06121201

Reaction notes

Loading…