Guanidine Hydrochloride → 6-Bromopyrido[2,3-d]pyrimidin-2-amine

Temperature

180 °C

5-bromo-2-fluoronicotinaldehyde (3.0 g, 14.78 mmol), guanidine hydrochloride (1.69 g, 17.74 mmol) and triethylamine (4.48 g, 44.35 mmol) were dissolved in 1-methyl-2-pyrrolidinone (15 mL), and the reaction mixture was stirred at 180° C. for 15 min under microwave. The mixture was cooled to RT, quenched with water (200 mL) and extracted with ethyl acetate (2×300 mL). The organic layers were combined, washed with water (3×50 mL) and brine (3×50 mL), dried over sodium sulfate, filtered, and concentrated to afford a crude product, which was purified by silica gel column chromatography (ethyl acetate:petroleum ether=3:1) to afford 6-bromopyrido[2,3-d]pyrimidin-2-amine (2.0 g, 60%) as a yellow solid. MS (ES+) C7H5BrN4 requires: 224, 226. Found: 225, 227 [M+H]+.

1. temperatureThe mixture was cooled to RT
2. customquenched with water (200 mL)
3. extractionextracted with ethyl acetate (2×300 mL)
4. washwashed with water (3×50 mL) and brine (3×50 mL)
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. customto afford a crude product, which
9. customwas purified by silica gel column chromatography (ethyl acetate:petroleum ether=3:1)

ORD record

ord-acc7f20b5861423b9911bac51a6faa56

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09126951B2