Acetone → DBF

HRID 2229100Notes

Reaction equation

HRID 2229100 reaction equation
[CH:1]1[CH:2]=[CH:3][C:4]([C:23]([OH:25])=[O:24])=[C:5]([C:7]2[C:17]3[CH:18]=[CH:19][C:20]([OH:22])=[CH:21][C:16]=3[O:15][C:14]3[C:8]=2[CH:9]=[CH:10][C:11]([CH:13]=3)=[O:12])[CH:6]=1.C(=O)([O-])[O-].[K+].[K+].[CH2:32](Cl)[C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1.[CH3:40][C:41]([CH3:43])=O>CN(C)C=O>[CH:36]1[CH:37]=[CH:38][C:33]([CH2:32][O:12][C:11]2[CH:10]=[CH:9][C:8]3[C:7]([C:5]4[C:4]([C:23]([O:25][CH2:40][C:41]5[CH:43]=[CH:5][CH:6]=[CH:1][CH:2]=5)=[O:24])=[CH:3][CH:2]=[CH:1][CH:6]=4)=[C:17]4[C:16]([O:15][C:14]=3[CH:13]=2)=[CH:21][C:20](=[O:22])[CH:19]=[CH:18]4)=[CH:34][CH:35]=1

Participants

6

Reactant 4

HCID 180AcetoneHCID 33832-(6-Hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acidHCID 7503Benzyl ChlorideHCID 11430Potassium Carbonate

Product 1

HCID 371436DBF

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
80 °C

Procedure

Fluorescein (40 g, 120.5 mmol) was dissolved in dimethylformamide (DMF, 500 mL) in a 2 L flask fitted with a mechanical stirrer then potassium carbonate (72 g, 521.7 mmol) was added in as a single portion. The reaction was heated to 80° C. then benzyl chloride (42 mL, 363.5 mmol) was added dropwise. After 24 h at 80° C. the reaction was cooled down to room temperature. Acetone (400 mL) was added and the product was allowed to precipitate overnight. The solid orange product was filtered, washed with acetone and dried in a vacuum oven at 50° C. The O-benzylfluorescein benzyl ester was obtained as an orange solid (36.4 g, 59%): mp 192-193° C. (Lit. 193-194° C.); 1H NMR (DMSO-d6): 4.97 (dd, 2H, J=12.2 Hz, J=15.3 Hz), 5.28 (s, 2H), 6.13 (d, 1H, J=1.9 Hz), 6.36 (dd, 1H, J=9.9 Hz), 6.77 (d, 1H, J=9.9 Hz), 6.82 6.77 (d, 1H, J=9.0 Hz), 6.90-6.98 (m, 3H), 7.14-7.27 (m, 4H), 7.33-7.52 (m, 6H), 7.78 (dt, 1H, J=1.65 Hz, J=7.4 Hz), 8.23 (dd, 1H, J=1.35 Hz, J=7.7 Hz); 13C NMR (DMSO-d6): 67.4, 70.7, 101.9, 105.2, 114.7, 115.0, 117.3, 128.3, 128.5, 128.7, 128.8, 128.9, 129.4, 130.0, 130.2, 130.6, 130.8, 131.2, 131.4, 133.8, 134.1, 135.3, 136.6, 150.1, 153.9, 158.7, 163.3, 165.5, 184.4; IR (nujol) cm−1 1728, 1643, 1595, 1517, 1462, 1377, 1261, 1211, 1081, 855. C34H24O5: Calc.(C, 79.67; H, 4.72) Found (C, 79.74; H, 4.79).

Workup

  1. customfitted with a mechanical stirrer
  2. temperatureAfter 24 h at 80° C. the reaction was cooled down to room temperature
  3. customto precipitate overnight
  4. filtrationThe solid orange product was filtered
  5. washwashed with acetone
  6. customdried in a vacuum oven at 50° C

Sources & evidence

ORD record
ord-b7614599a773446caf015d8577b37e98
Source dataset
uspto-grants-2002_07
Patent number
US06420131B1

Reaction notes

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