2,5-Hexanedione → 2-(2,5-Dimethyl-1H-pyrrol-1-yl)-4,6-dimethylpyridine

HRID 73479

Reaction equation

HRID 73479 reaction equation
[CH3:1][C:2]1[CH:7]=[C:6]([CH3:8])[N:5]=[C:4]([NH2:9])[CH:3]=1.[CH2:10]([CH2:14][C:15](=O)[CH3:16])[C:11]([CH3:13])=O>C1(C)C=CC=CC=1.CC1C=CC(S(O)(=O)=O)=CC=1>[CH3:16][C:15]1[N:9]([C:4]2[CH:3]=[C:2]([CH3:1])[CH:7]=[C:6]([CH3:8])[N:5]=2)[C:11]([CH3:13])=[CH:10][CH:14]=1

Participants

5

Reactant 2

HCID 80352,5-HexanedioneHCID 215072-Amino-4,6-dimethylpyridine

Product 1

HCID 224907362-(2,5-Dimethyl-1H-pyrrol-1-yl)-4,6-dimethylpyridineYield 91%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 1140TolueneSolvent

Procedure

To a solution of 4,6-dimethyl-2-aminopyridine (7, 12.2 g, 100 mmol) in toluene (100 mL) was added acetonylacetone (12.3 mL, 105 mmol) and p-TsOH (190 mg, 1.0 mmol). The reaction mixture was heated in a Dean-Stark apparatus under reflux for 6 h. After cooling to room temperature, the mixture was concentrated with a rotary evaporator, and the resulting brown oil was purified by flash column chromatography (EtOAc/hexanes, 1:19-1:9) to give 8 (18.2 g, 91 mmol, 91%) as a pale yellow solid: 1H NMR (500 MHz, CDCl3) δ 2.13 (s, 6H), 2.40 (s, 3H), 2.56 (s, 3H), 5.88 (s, 2H), 6.85 (s, 1H), 7.00 (s, 1H); 13C NMR (125 MHz, CDCl3) δ 13.4, 21.2, 24.4, 106.8, 119.9, 123.1, 128.6, 149.6, 151.7, 158.4; LCQ-MS (M+H+) calcd for C13H17N2 201. found 201; LC-TOF-MS (M+H+) calcd for C13H17N2 201.13917. found 201.13881.

Workup

  1. temperatureThe reaction mixture was heated in a Dean-Stark apparatus
  2. temperatureunder reflux for 6 h
  3. concentrationthe mixture was concentrated with a rotary evaporator
  4. customthe resulting brown oil was purified by flash column chromatography (EtOAc/hexanes, 1:19-1:9)

Sources & evidence

ORD record
ord-12c24e16ac7245f5892b4517493a0d94
Source dataset
uspto-grants-2014_09
Patent number
US08829187B1

Linked notes

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