Diethyl Ether → 2-Amino-5,6-dichloro-3-(1-hydroxyethyl)pyrazine

In 3 ml of tetrahydrofuran there was dissolved 2-amino-5,6-dichloro-3-formylpyrazine (144 mg; 0.75 mM) prepared as in Example 1, Step B above, and then 2 ml of ether was added. The reaction mixture was cooled in a dry ice/acetone bath, and methyl magnesium bromide (0.75 ml of 11% solution in ether; 0.75 mM) was then added dropwise over 10 minutes. The reaction mixture was stirred for 0.25 hour at the cooled temperature, allowed to gradually warm to room temperature, and then stirred an additional 0.5 hour. Ammonium chloride solution was then added with stirring for 0.25 hour, followed by addition of more ether. Layers separated; the organic layer was washed with water; the aqueous layer extracted three times with ether, washed with water. The solvent was evaporated and the residue dried, then passed through a silica gel column, eluting first with dichloromethane, then 5% ethyl acetate in dichloromethane. Product yield was 98 mg.

1. additionwas added
2. temperatureThe reaction mixture was cooled in a dry ice/acetone bath
3. stirringstirred an additional 0.5 hour
4. stirringwith stirring for 0.25 hour
5. customLayers separated
6. washthe organic layer was washed with water
7. extractionthe aqueous layer extracted three times with ether
8. washwashed with water
9. customThe solvent was evaporated
10. customthe residue dried
11. washeluting first with dichloromethane

ORD record

ord-64c1f5eb2bc848e8aa10cf7ea825fed9

Source dataset

uspto-grants-1985_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04512991