4-Amino-1,2,4-triazole → 2-Nitrothiophen-3-amine

Temperatur

5 °C

12.8 g of 85% 2-nitro-thiophene and 33.6 g of 4-amino-4H-1,2,4-triazole (1-1, 3-4) were dissolved at ambient temperature in 100 ml of anhydrous dimethyl-sulfoxide and the solution was cooled down to 5° C. A solution of 22.4 g of potassium terbutylate in 100 ml of anhydrous dimethyl-sulfoxide was added over about 15 minutes and the suspension was stirred for a further 15 minutes at ambient temperature, then poured into 0.6 liter of a saturated solution of ammonium chloride. Extraction was carried out 3 times with 500 ml of ethyl acetate and the extracts were washed 3 times with 400 ml of water, dried, filtered and evaporated to dryness. The product was dissolved in 800 ml of methylene chloride, followed by filtration and evaporation to dryness. The product was crystallized from 20 ml of isopropyl ether and the crystals were separated out, washed with isopropyl ether and then dried at 80° C. under reduced pressure to obtain 5.1 g of the expected product melting at 159° C.

1. extractionExtraction
2. washthe extracts were washed 3 times with 400 ml of water
3. customdried
4. filtrationfiltered
5. customevaporated to dryness
6. dissolutionThe product was dissolved in 800 ml of methylene chloride
7. filtrationfollowed by filtration and evaporation to dryness
8. customThe product was crystallized from 20 ml of isopropyl ether
9. customthe crystals were separated out
10. washwashed with isopropyl ether
11. customdried at 80° C. under reduced pressure

ORD-Eintrag

ord-99c51f70cc824caa973f05ea494f80d2

Quelldatensatz

uspto-grants-1995_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05389634