Potassium Fluoride → 6-Chloro-3-fluoro-4H-thieno[3,2-e]-1,2,4-thiadiazine 1,1-dioxide

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Reaction Conditions

Reaction Steps

A mixture of 3,6-dichloro-4H-thieno[3,2-e]-1,2,4-thiadiazine 1,1-dioxide (1.02 g, 3.95 mmol), potassium fluoride (688 mg, 11.9 mmol) and hexadecyltrimethylammonium bromide (43 mg, 0.12 mmol) in dry 1-methyl-2-pyrrolidinone (4 ml) was stirred for 20 h at 130° C. under nitrogen to form 6-chloro-3-fluoro-4H-thieno[3,2-e]-1,2,4-thiadiazine 1,1-dioxide. The mixture was allowed to cool to room temperature and then reacted directly with 1-ethylcyclohexylamine hydrochloride (0.8 g, 5.93 mmol) and triethylamine (1.65 ml, 11.9 mmol) for 30 h at 75° C. in the sealed flask. The cooled mixture was poured into water, acidified to pH <2 with 1N hydrochloric acid and extracted with ethyl acetate. The organic phase was dried with sodium sulphate and evaporated to dryness to give the pure title compound; mp 244-246° C.; 1H-NMR (DMSO-d6): δ0.79 (t, 3H), 1.70-1.93 (m, 8H), 1.96-2.08 (m, 2H), 2.13-2.25 (m, 2H), 7.09 (s, 1H), 7.24 (br s, 1 H), 10.57 (br s, 1 H).

Provenance & Evidence