Sulfuric Acid → HCID 178477915, compound

Temperature

-15 °C

6-Chloropyridine-2,3-diamine (Example 23, Step 1) (226 mg, 1.57 mmol) was taken up in warm water (6.3 ml). Sulfuric acid (0.26 ml, 4.72 mmol) was added, and the solution was cooled to −15° C. In a separate flask, sodium nitrite (119 mg, 1.73 mmol) was dissolved in 2 mL cold water. The sodium nitrite solution was added dropwise to the reaction mixture over 15 minutes. The mixture was allowed to stir at −15° C. for 1 hour, then filtered, and the yellow-brown precipitate was collected. The solid was recrystallized from water to yield the title compound as a yellow-brown solid. The filtrate from the separation was neutralized with aqueous sodium bicarbonate and extracted 3× with ethyl acetate. All organic fractions were combined, washed with brine, dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo to give an additional portion of the title compound as a yellow-brown solid.

1. filtrationfiltered
2. customthe yellow-brown precipitate was collected
3. customThe solid was recrystallized from water

ORD record

ord-6eea1d0c5f864229b2ee7ea84d9413b8

Source dataset

uspto-grants-2013_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08344144B2