1,1'-Carbonyldiimidazole → 3,4,4a,5-tetrahydro-5-methylpyrimido-[1,6-a]indol-1(2H)-one

HRID 1657296Notes

Reaction equation

HRID 1657296 reaction equation
[CH3:1][CH:2]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[NH:4][CH:3]1[CH2:11][CH2:12][NH2:13].[C:14](N1C=CN=C1)(N1C=CN=C1)=[O:15]>O1CCCC1.C1(C)C=CC=CC=1>[CH3:1][CH:2]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[N:4]2[C:14](=[O:15])[NH:13][CH2:12][CH2:11][CH:3]12

Participants

5

Reactant 2

HCID 682631,1'-CarbonyldiimidazoleHCID 197871342-(2,3-Dihydro-3-methylindol-2-yl)ethylamine

Product 1

HCID 151870443,4,4a,5-tetrahydro-5-methylpyrimido-[1,6-a]indol-1(2H)-oneYield 47.4%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
110 °C

Procedure

To a solution of crude 2-(2,3-dihydro-3-methylindol-2-yl)ethylamine (1.75 g) in tetrahydrofuran (12 ml) at room temperature was added in small portions 1,1'-carbonyldiimidazole (1.1 g). After being stirred for 2 hours, the reaction mixture was evaporated in vacuo. The oil obtained was dissolved in toluene (25 ml) and the solution was heated at 110° C. for 1.5 hours. After evaporation of the solvent, the residue was purified by silica gel column chromatography (1% methanol-chloroform) to give crystals. Recrystallization from chloroform-ethyl acetate-hexane gave 3,4,4a,5-tetrahydro-5-methylpyrimido-[1,6-a]indol-1(2H)-one (0.65 g).

Workup

  1. customthe reaction mixture was evaporated in vacuo
  2. customThe oil obtained
  3. customAfter evaporation of the solvent
  4. customthe residue was purified by silica gel column chromatography (1% methanol-chloroform)
  5. customto give crystals
  6. customRecrystallization from chloroform-ethyl acetate-hexane

Sources & evidence

ORD record
ord-f67374181e114d1c9d65fba071b7f8fb
Source dataset
uspto-grants-1993_10
Patent number
US05256780

Reaction notes

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