Boron trifluoride etherate → HCID 21480715, compound

HRID 1721800Notes

Reaction equation

HRID 1721800 reaction equation
B(F)(F)F.CC[O:7]CC.N[C:11]1[CH:24]=[CH:23][C:22]2[CH:21]3[CH2:25][C:14]([C:27]([O:29][CH3:30])=[O:28])([C:15]4[C:20]3=[CH:19][CH:18]=[C:17]([Cl:26])[CH:16]=4)[C:13]=2[CH:12]=1.N(OC(C)(C)C)=O.C(=O)([O-])[O-].[K+].[K+].C1C2C(=CC=CC=2)C=CC=1O>C(Cl)Cl.FC(F)(F)C(O)=O.Cl.O>[Cl:26][C:17]1[CH:18]=[CH:19][C:20]2[CH:21]3[CH2:25][C:14]([C:27]([O:29][CH3:30])=[O:28])([C:13]4[C:22]3=[CH:23][CH:24]=[C:11]([OH:7])[CH:12]=4)[C:15]=2[CH:16]=1

Participants

10

Reactant 5

HCID 8000Boron trifluoride etherateHCID 86632-NaphtholHCID 10906Tert-Butyl nitriteHCID 11430Potassium CarbonateHCID 21480627HCID 21480627, compound

Product 1

HCID 21480715HCID 21480715, compoundYield 80.2%

Reagents, catalysts & solvents 4

HCID 313Hydrochloric AcidSolventHCID 962WaterSolventHCID 6344DichloromethaneSolventHCID 6422Trifluoroacetic acidSolvent

Conditions

Temperature
0 °C

Procedure

To boron trifluoride etherate (0.413 mL, 3.36 mmol, 1.5 eq) cooled to -15° C. under nitrogen was added a solution of methyl 2-amino-7-chloro-9,10-dihydro-9,10-methano-9-anthracenecarboxylate (described in example 35c) (670 mg, 2.24 mmol) in methylene chloride (5 mL). This was followed by t-butyl nitrite (0.320 mL, 2.69 mmol, 1.2 eq) resulting in a precipitate and a dark blue-green solution color. After 10 min at -15° C., the reaction was warmed to 0° C. and stirred for additional 20 min The diazonium salt was precipitated by pentane dilution (100 mL). The precipitate was filtered and rinsed with cold diethyl ether to recover 650 mg of the crude salt. The diazonium salt was added to a solution of potassium carbonate (155 mg, 0.5 eq) in trifluoroacetic acid (5 mL) at 0° C. The reaction was brought to reflux for 20 h at which time the alkaline beta-naphthol test for diazonium salt was negative. Water (5 mL) was added to quench the reaction and the trifluoroacetic acid was removed in vacuo. The crude reaction mixture was diluted with 3N HCl (30 mL) and extracted with ethyl acetate (3×25 mL). Combined organic extracts were dried over anhydrous magnesium sulfate, filtered, and reduced to an oil. The reaction product was purified by flash chromatography over silica gel (35 mL, eluent; 10% ethyl acetate in hexane) to yield 540 mg (80%) of the title compound as a white solid. TLC analysis (Rf 0.21, 10% ethyl acetate in hexane). MS (CI, CH4) m/z 301 (M+1,100), 303 (42), 329 (M+29,10), 269 (31), 241 (56) b. 2-Chloro-7-hydroxy-9,10-dihydro-9,10-methano-9-anthracene-carboxylic acid

Workup

  1. customresulting in a precipitate
  2. customwas precipitated by pentane dilution (100 mL)
  3. filtrationThe precipitate was filtered
  4. washrinsed with cold diethyl ether
  5. customto recover 650 mg of the crude salt
  6. customto quench
  7. customthe reaction
  8. customthe trifluoroacetic acid was removed in vacuo
  9. customThe crude reaction mixture
  10. extractionextracted with ethyl acetate (3×25 mL)
  11. dry with materialCombined organic extracts were dried over anhydrous magnesium sulfate
  12. filtrationfiltered
  13. customThe reaction product was purified by flash chromatography over silica gel (35 mL, eluent; 10% ethyl acetate in hexane)

Sources & evidence

ORD record
ord-4951cf0bfa8749429c1bca5cb59e4c8e
Source dataset
uspto-grants-1996_04
Patent number
US05512575

Reaction notes

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