Acetic Anhydride → HCID 20148569, compound

Temperature

140 °C

A suspension of N,N-dimethyl-N'-(4-oxido-thieno[3,2-b]pyridine-2-sulfonyl)formamidine (6.23 g, 22.6 mmol) in acetic anhydride (70 ml), under a nitrogen atmosphere, was heated at 140° C. for 20-22 hours to give a dark solution. The excess acetic anhydride was removed on a rotary evaporator and 6 N HCl (90 ml) was added to the residue and it was warmed at 80° C. for four hours. This reaction mixture was cooled and ice was added as product began to precipitate. Upon standing several crops were collected by filtration. The combined crude product (2.2 g) was dissolved in a large volume of boiling water, filtered and allowed to cool. Pure product was obtained (1.72 g, 33% yield). This material was recrystallized by dissolution in a minimum volume of hot dimethylsulfoxide. This solution was treated with charcoal, filtered, and diluted with ethanol as product crystallized (1.3 g), m.p. >300° C.

1. customto give a dark solution
2. customThe excess acetic anhydride was removed on a rotary evaporator and 6 N HCl (90 ml)
3. additionwas added to the residue and it
4. temperaturewas warmed at 80° C. for four hours
5. temperatureThis reaction mixture was cooled
6. additionice was added as product
7. customto precipitate
8. filtrationwere collected by filtration
9. dissolutionwas dissolved in a large volume of boiling water
10. filtrationfiltered
11. temperatureto cool
12. customPure product was obtained (1.72 g, 33% yield)
13. customThis material was recrystallized by dissolution in a minimum volume of hot dimethylsulfoxide
14. additionThis solution was treated with charcoal
15. filtrationfiltered
16. additiondiluted with ethanol as product
17. customcrystallized (1.3 g), m.p. >300° C.

ORD record

ord-dcc7984c6b2a483ab6824a560d76b438

Source dataset

uspto-grants-1988_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04731368