Acetone → HCID 59372995, compound

HRID 1471334Notes

Reaction equation

HRID 1471334 reaction equation
[NH2:1][C:2]1[CH:17]=[CH:16][C:5]2[N:6]([C:9]3[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=3[OH:15])[CH:7]=[N:8][C:4]=2[CH:3]=1.[CH2:18](Br)[C:19]#[CH:20].C([O-])([O-])=O.[K+].[K+].CC(C)=O>C1(C)C=CC=CC=1>[NH2:1][C:2]1[CH:17]=[CH:16][C:5]2[N:6]([C:9]3[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=3[O:15][CH2:20][C:19]#[CH:18])[CH:7]=[N:8][C:4]=2[CH:3]=1

Participants

6

Reactant 4

HCID 180AcetoneHCID 7842Propargyl bromideHCID 11430Potassium CarbonateHCID 59373055HCID 59373055, compound

Product 1

HCID 59372995HCID 59372995, compoundYield 39%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
70 °C

Procedure

A suspension of 5-amino-1-(2-hydroxyphenyl)benzimidazole (4) (499 mg, 2.21 mmol), 80% propargyl bromide (2.43 mmol) in toluene (271 μL), K2CO3 (398 mg, 2.88 mmol), and acetone (15 mL) is stirred at 70° C. under argon for 18.5 h and then cooled to room temperature. The mixture is concentrated, diluted with H2O (35 mL), and extracted with ethyl acetate (100 mL and 50 mL). The extract is washed (brine) and dried. After solvent removal at reduced pressure, the residue is purified on silica gel (2% to 7% methanol/ethyl acetate) to give 213 mg (39%) of 5 as a light-brown solid, mp 40-42° C. IR 3379, 2966, 1512, 1239 cm−1; 1H NMR (CDCl3) δ 2.51 (t, J=2.4 Hz, 1H, C≡CH), 3.09 (bs, 2H, NH2), 4.68 (d, J=2.4 Hz, 2H, CH2C≡CH), 6.74 (dd, J=8.4 Hz, 2.1 Hz, 1H, 6-BenzimidH), 7.14 (d, J=8.4 Hz, 1H, 7-BenzimidH), 7.16 (d, J=2.1 Hz, 1H, 4-BenzimidH), 7.19 (m, 1H, 3-PhH), 7.29 (m, 1H, 5-PhH), 7.42-7.49 (m, 2H, 4,6-PhH), 8.01 ppm (s, 1H, 2-BenzimidH). HRMS calcd C16H13N3O [M+H]+ 264.1137. found 264.1129.

Workup

  1. temperaturecooled to room temperature
  2. concentrationThe mixture is concentrated
  3. additiondiluted with H2O (35 mL)
  4. extractionextracted with ethyl acetate (100 mL and 50 mL)
  5. washThe extract is washed (brine)
  6. customdried
  7. customAfter solvent removal at reduced pressure
  8. customthe residue is purified on silica gel (2% to 7% methanol/ethyl acetate)

Sources & evidence

ORD record
ord-b497fb9ceadc4392acd0ff941c1f3b5c
Source dataset
uspto-grants-2015_04
Patent number
US09012217B2

Reaction notes

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