2-Amino-4-bromopyridine → tert-Butyl 7-bromo-3,4-dihydropyrido[4',3':4,5]imidazo[1,2-a]pyridine-2(1H)-carboxylate

HRID 882066Notes

Reaction equation

HRID 882066 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([Br:8])[CH:5]=[CH:4][N:3]=1.Br[CH:10]1[C:15](=O)[CH2:14][CH2:13][N:12]([C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])[CH2:11]1>C1(C)C=CC=CC=1>[Br:8][C:6]1[CH:5]=[CH:4][N:3]2[C:10]3[CH2:11][N:12]([C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])[CH2:13][CH2:14][C:15]=3[N:1]=[C:2]2[CH:7]=1

Participants

4

Reactant 2

HCID 6932822-Amino-4-bromopyridineHCID 106839701-tert-Butyloxycarbonyl-3-bromo-4-oxopiperidine

Product 1

HCID 67988849tert-Butyl 7-bromo-3,4-dihydropyrido[4',3':4,5]imidazo[1,2-a]pyridine-2(1H)-carboxylateYield 32%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
105 °C

Procedure

2-Amino-4-bromopyridine (786 mg, 4.55 mmol) and tert-butyl 3-bromo-4-oxopiperidine-1-carboxylate (1.39 g, 5.00 mmol) were combined in toluene (20 mL) and heated at 105° C. for 16 h. The mixture was concentrated and purified by flash column chromatography (40 g ISCO column eluting with methylene chloride and a methanol/ammonia mixture (10:1); gradient 100% methylene chloride to 80% methylene chloride over 30 min at 40 mL/min) to provide the title compound (512 mg, 32%) as a white solid: 1H NMR (500 MHz, CDCl3) δ 7.93 (s, 1H), 7.46 (d, J=9.1 Hz, 1H), 7.22 (d, J=9.1 Hz, 1H), 4.69 (br s, 2H), 3.85 (br s, 2H), 2.93 (br s, 2H), 1.51 (s, 9H).

Workup

  1. concentrationThe mixture was concentrated
  2. custompurified by flash column chromatography (40 g ISCO column
  3. washeluting with methylene chloride

Sources & evidence

ORD record
ord-3e19d38268d844bc911584b696ce5503
Source dataset
uspto-grants-2015_03
Patent number
US08993765B2

Reaction notes

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