Acetyl chloride → 3-Aminoimidazo(1,2-a)pyridine

To a suspension of amino-pyridine derivative Gen-1 (1 eq.) in toluene are added the aldehyde RzCHO (1 eq.) and benzotriazole (1 eq.). The mixture is stirred at r.t. overnight. Additional aldehyde reagent (0.06 eq.) and benzotriazole (0.06 eq.) are added. After 4 h stirring, potassium cyanide (1.2 eq.) is added, followed by EtOH. The reaction mixture is stirred at r.t. for 5 days. The crude product mixture is then quenched with a 3 M NaOH solution. Solvents are evaporated carefully in vacuo. The residue is diluted with water and EtOAc. The aqueous layer is extracted with EtOAc. The combined organic layers are washed with water and brine, dried over Na2SO4 and concentrated in vacuo. The crude product mixture is dissolved in EtOH and carefully added to a solution of acetyl chloride (2.1 eq.) in EtOH at 0° C. The resulting reaction mixture is stirred at r.t. overnight and then concentrated to dryness to afford the corresponding imidazo[1,2-a]pyridin-3-ylamine as hydrochloride salt.

1. stirringAfter 4 h stirring
2. stirringThe reaction mixture is stirred at r.t. for 5 days
3. customThe crude product mixture is then quenched with a 3 M NaOH solution
4. customSolvents are evaporated carefully in vacuo
5. additionThe residue is diluted with water and EtOAc
6. extractionThe aqueous layer is extracted with EtOAc
7. washThe combined organic layers are washed with water and brine
8. dry with materialdried over Na2SO4
9. concentrationconcentrated in vacuo
10. dissolutionThe crude product mixture is dissolved in EtOH
11. customThe resulting reaction mixture
12. stirringis stirred at r.t. overnight
13. concentrationconcentrated to dryness

ORD record

ord-06fa92e064d24a1ea43f324b3b93b1dc

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09249141B2