Hydrogen Peroxide → 5-amino-3-methylisothiazole-4-carbonitrile

A 3 liter multi-neck flask was equipped with dropping funnel, air stirrer, thermometer and condenser. To the flask was charged 3-amino-2-cyanothiocrotonamide 1 (40 g, 0.283 mole) and methanol (2 liters). A dark, almost homogeneous solution resulted. Hydrogen peroxide (80 ml, 100 vol, 0.7 mole) was then added dropwise over a period of 10 minutes. On completion of the addition the reaction mixture was slowly heated to reflux over a period of 30 mins and refluxing continued for 30 mins. TLC indicated complete reaction (silica, CHCl3). The hot solution was treated with activated carbon and then filtered through kieselguhr. The filtrates were then concentrated by evaporation to a volume of about 300 ml. The concentrated slurry was poured into ice-water (1400-1500 g) and the resultant product filtered-off, washed with water (2×150 ml), pulled as dry as possible on the filter and finally dried in a vacuum oven at 55° C.

1. customA 3 liter multi-neck flask was equipped
2. customA dark, almost homogeneous solution resulted
3. additionOn completion of the addition the reaction mixture
4. temperaturewas slowly heated
5. temperatureto reflux over a period of 30 mins
6. temperaturerefluxing
7. additionThe hot solution was treated with activated carbon
8. filtrationfiltered through kieselguhr
9. concentrationThe filtrates were then concentrated by evaporation to a volume of about 300 ml
10. additionThe concentrated slurry was poured into ice-water (1400-1500 g)
11. washthe resultant product filtered-off, washed with water (2×150 ml)
12. customas dry as possible on the
13. filtrationfilter
14. customfinally dried in a vacuum oven at 55° C.

ORD record

ord-0a948f0d6280440d98721e3cb7df2a10

Source dataset

uspto-grants-2001_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06187084B1