Triphenylphosphine → 2-(9H-carbazol-2-yl)benzo[d]oxazole

HRID 1509641Notes

Reaction equation

HRID 1509641 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[C:10]1[CH:15]=[CH:14][C:13]([C:16]2[O:17][C:18]3[CH:24]=[CH:23][CH:22]=[CH:21][C:19]=3[N:20]=2)=[CH:12][CH:11]=1)([O-])=O.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>>[CH:14]1[C:15]2[NH:1][C:4]3[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=3)[C:10]=2[CH:11]=[CH:12][C:13]=1[C:16]1[O:17][C:18]2[CH:24]=[CH:23][CH:22]=[CH:21][C:19]=2[N:20]=1

Participants

3

Reactant 2

HCID 11776TriphenylphosphineHCID 1181140332-(2'-Nitrobiphenyl-4-yl)benzo[d]oxazole

Product 1

HCID 233626352-(9H-carbazol-2-yl)benzo[d]oxazoleYield 83.4%

Conditions

Temperature
180 °C

Procedure

To a three-necked flask equipped with a magnetic stir bar and a condenser was added 2-(2′-nitrobiphenyl-4-yl)benzo[d]oxazole (1.08 g, 3.41 mmol, 1.0 eq) and PPh3 (4.48 g, 17.07 mmol, 5.0 eq). The flask was evacuated and back-filled with nitrogen. The evacuation and back-fill procedure was repeated twice. Then 1,2-dichlorobenzene (20 mL) was added under the protection of nitrogen. The mixture was stirred in an oil bath at a temperature of 175-185° C. for 24 hours, and cooled. The solvent was removed by distillation under high vacuum. Some ethyl acetate and dichloromethane was added to the residue and stirred at room temperature overnight. The residue was filtered and washed with dichloromethane. The collected solid was dried in air to get the desired product as an off-white solid 809 mg. The filtrate was concentrated and the residue was purified through column chromatography on silica gel using hexane and ethyl acetate (10:1-5:1-3:1) as an eluent to obtain the desired product (117 mg in 96% total yield). 1H NMR (DMSO-d6, 400 MHz): δ 7.25 (t, J=7.6 Hz, 1H), 7.41-7.52 (m, 3H), 7.60 (d, J=8.4 Hz, 1H), 7.82-7.86 (m, 2H), 8.05 (dd, J=8.4, 1.2 Hz, 1H), 8.24 (d, J=7.2 Hz, 1H), 8.34-8.37 (m, 2H), 11.63 (s, 1H).

Workup

  1. customTo a three-necked flask equipped with a magnetic stir bar and a condenser
  2. customThe flask was evacuated
  3. additionback-filled with nitrogen
  4. additionThen 1,2-dichlorobenzene (20 mL) was added under the protection of nitrogen
  5. temperaturecooled
  6. customThe solvent was removed by distillation under high vacuum
  7. additionSome ethyl acetate and dichloromethane was added to the residue
  8. stirringstirred at room temperature overnight
  9. filtrationThe residue was filtered
  10. washwashed with dichloromethane
  11. customThe collected solid was dried in air

Sources & evidence

ORD record
ord-3a3bfe2a2bc849939a29e7cd75485207
Source dataset
uspto-grants-2015_12
Patent number
US09224963B2

Reaction notes

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