Boron trifluoride → 6-(2-Phenylethenyl)-1,3-benzothiazol-2(3H)-one

Temperature

0 °C

The compound obtained in Step B (1 g) is dissolved in HBF4 (10 ml) and the mixture is cooled to 0° C. 0.44 g of NaNO2 previously dissolved in water is then added and the reaction is stirred at 0° C. for 1 hour. The resulting precipitate is filtered off and washed with ether, ground with BF3 (4.5 mmol) and palladium acetate (0.2 mmol), and then placed under a nitrogen atmosphere before the addition of 15.1 ml of anhydrous dioxane. The reaction mixture is stirred for 5 hours at ambient temperature and then hydrolysis is carried out with 50 ml of water and extraction is carried out twice with 30 ml ether each time. The organic phase is dried over MgSO4 and then evaporated under reduced pressure. The resulting precipitate is washed with isopropyl ether and recrystallised from methanol.

1. additionis then added
2. filtrationThe resulting precipitate is filtered off
3. stirringThe reaction mixture is stirred for 5 hours at ambient temperature
4. customhydrolysis
5. extractionis carried out with 50 ml of water and extraction
6. dry with materialThe organic phase is dried over MgSO4
7. customevaporated under reduced pressure
8. washThe resulting precipitate is washed with isopropyl ether
9. customrecrystallised from methanol

ORD record

ord-3d90499e44dc45a49dd83d8f19846c8b

Source dataset

uspto-grants-2005_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06919362B2