Hydrochloric Acid → O-methyl-N-(2-chloro-5-thiazolylmethyl)-N'-nitroisourea

5-(Aminomethyl)-2-chlorothiazole (7.43 g, 50.0 mmol) was dissolved in water (96 ml), and concentrated hydrochloric acid (4.22 ml, 50.0 mmol) was added. To this reaction mixture was added O-methyl-N-nitroisourea (6.25 g, 52.5 mmol) and chloroform (30 ml), and adjusted to pH 6.7 with aqueous sodium hydroxide solution (0.5 N) using pH meter. After 24 hours of stirring at room temperature, maintaining pH 6.7, the organic phase was separated from the water phase. The water phase was extracted with chloroform (100 ml), and the combined organic phase was concentrated under reduced. Water (50 ml) was added to the residue to stir for a while. The resulting crystals were collected by filtration under reduced pressure, and washed with water. The washed crystals were dried under reduced pressure (80° C., 2 hours) to provide 7.80 g (62.2% yield) of O-methyl-N-(2-chloro-5-thiazolylmethyl)-N'-nitroisourea.

1. temperaturemaintaining pH 6.7
2. customthe organic phase was separated from the water phase
3. extractionThe water phase was extracted with chloroform (100 ml)
4. concentrationthe combined organic phase was concentrated
5. additionWater (50 ml) was added to the residue
6. stirringto stir for a while
7. filtrationThe resulting crystals were collected by filtration under reduced pressure
8. washwashed with water
9. customThe washed crystals were dried under reduced pressure (80° C., 2 hours)

ORD record

ord-79683c294f224ad0adf5f370da689162

Source dataset

uspto-grants-2000_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06166215