1,2-Dibromoethane → 3-(5-Chloro-2-thienyl)-5,6-dihydro-1,4,2-oxathiazine

Temperature

5 °C

Methyl 5-chloro-2-thiophenecarbodithioate (61.4g, 0.29 mol) was suspended in methanol (400 ml) with finely powdered hydroxylamine hydrochloride (25g). With stirring, triethylamine (50 ml) in methanol (50 ml) was added dropwise to the suspension, to produce a reaction mixture. During this addition, the reaction mixture was cooled to 5° C. Stirring of the reaction mixture was continued until an orange (from red) color developed in the reaction mixture. Additional triethylamine (100 ml) was then added at once, followed by 1,2-dibromoethane (20 ml). The resultant reaction mixture was then stirred overnight at ambient temperature. The reaction mixture was then refluxed with removal of solvent until a precipitate appeared. The reaction mixture was then cooled and water was added. The reaction mixture was then filtered and the solid collected on the filter was recrystallized from ethanol to produce 3-(5-chloro-2-thienyl)-5,6-dihydro-1,4,2-oxathiazine (mp 74-77° C., 21.4g. Found C 38.5, H 2.94, N 6.45, C7H6CINOS2 requires C 38.27, H 2.73, N 6.38)

1. customto produce a reaction mixture
2. additionDuring this addition
3. stirringStirring of the reaction mixture
4. customThe resultant reaction mixture
5. stirringwas then stirred overnight at ambient temperature
6. temperatureThe reaction mixture was then refluxed with removal of solvent until a precipitate
7. temperatureThe reaction mixture was then cooled
8. filtrationThe reaction mixture was then filtered
9. customthe solid collected on the filter
10. customwas recrystallized from ethanol

ORD record

ord-44b801f4036446b6809043419931eea1

Source dataset

uspto-grants-2002_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06372297B1