Boron tribromide → HCID 135398696, compound

HRID 1970781Notes

Reaction equation

HRID 1970781 reaction equation
[CH2:1]([C:8]1[C:9]([NH:22][C:23](=[O:31])[CH2:24][C:25]2[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=2)=[N:10][CH:11]=[C:12]([C:14]2[CH:19]=[CH:18][C:17]([O:20]C)=[CH:16][CH:15]=2)[N:13]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.B(Br)(Br)Br.C(=O)(O)[O-].[Na+]>ClCCl>[CH2:1]([C:8]1[C:9]([NH:22][C:23](=[O:31])[CH2:24][C:25]2[CH:26]=[CH:27][CH:28]=[CH:29][CH:30]=2)=[N:10][CH:11]=[C:12]([C:14]2[CH:19]=[CH:18][C:17]([OH:20])=[CH:16][CH:15]=2)[N:13]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 25134Boron tribromideHCID 516892Sodium BicarbonateHCID 67002629HCID 67002629, compound

Product 1

HCID 135398696HCID 135398696, compoundYield 44.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

Under an argon atmosphere, 3-benzyl-5-(4-methoxyphenyl)-2-(phenylacetylamino)pyrazine (c-16) (250 mg, 611 was dissolved in anhydrous dichloromethane (15 mL) and to this was added 1.0 M solution of boron tribromide in dichloromethane (2.15 mL, 2.15 mmol) while stirring at room temperature, and heated to reflux for 15 h. After refluxing, it was cooled to room temperature, and to this was added saturated aqueous solution of sodium bicarbonate to stop the reaction, and concentrated under reduced pressure using a rotary evaporator to remove dichloromethane. The suspension was filtered and the residue was dried to give 270 mg of the crude product as a pale yellow solid. Recrystallization from methanol gave 3-benzyl-5-(4-hydroxyphenyl)-2-(phenylacetylamino)pyrazine (h-coelenteramide) (c-13) as a colorless solid (107 mg, 44.1%). Rf=0.20 (dichloromethane/ethyl acetate=4/1). Mp. 259-261° C. UV (MeOH) λmax (log ε) 332 (4.38), 294.5 (4.38), 276 (4.35). UV (pH 7.4 PB, 1% DMSO) λmax (log ε) 345.5 (3.52), 303 (3.57). 1H NMR (400 MHz, DMSO-d6) δ 3.67 (s, 2H), 4.01 (s, 2H), 6.84-6.89 (AA′BB′, 2H), 7.02 (d, J=6.9 Hz, 2H), 7.11-7.23 (m, 4H), 7.23-7.30 (m, 1H), 7.32-7.37 (m, 4H), 7.90-7.95 (AA′BB′, 2H), 8.82 (s, 1H), 9.87 (s, 1H), 10.48 (s, 1H). 13C NMR (75.5 MHz, DMSO-d6) δ 39.7, 42.4, 115.8 (2C), 126.2, 126.4, 126.7, 128.1 (2C), 128.3 (2C), 128.4 (2C), 128.9 (2C), 129.3 (2C), 135.6, 136.9, 138.3, 143.3, 148.6, 150.5, 159.1, 169.9. IR (KBr, cm−1) 662, 702, 712, 727, 843, 1157, 1173, 1231, 1281, 1321, 1355, 1368, 1452, 1495, 1523, 1541, 1584, 1595, 1611, 1668, 3063, 3169, 3264. HRMS (FAB+) m/z 396.1706 (M+H, C25H22N3O2 requires 396.1712).

Workup

  1. temperatureheated
  2. temperatureto reflux for 15 h
  3. temperatureAfter refluxing
  4. temperatureit was cooled to room temperature
  5. customthe reaction
  6. concentrationconcentrated under reduced pressure
  7. customa rotary evaporator
  8. customto remove dichloromethane
  9. filtrationThe suspension was filtered
  10. customthe residue was dried
  11. customto give 270 mg of the crude product as a pale yellow solid
  12. customRecrystallization from methanol

Sources & evidence

ORD record
ord-7fe663ffef0a46a59b65a75a6150c2d0
Source dataset
uspto-grants-2013_04
Patent number
US08431525B2

Reaction notes

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