Réaction #336805

Équation de réaction

fluorescein isothiocyanate

Et3N

→

fluorescein

Solvants

DMF

CH2Cl2

Conditions de réaction

Traitement

1. 1
   AutreAn orange colored precipitate was immediately formed
2. 2
   Autreremained during the entire period of the reaction
3. 3
   AutreAfter completion of the reaction
4. 4
   Filtrationthe insoluble precipitate was filtered off
5. 5
   Autreand the solvent was removed under reduced pressure
6. 6
   workup.ADDITIONThe residue was diluted with CH2Cl2 (15 mL)
7. 7
   Lavagewashed with 1N HCl (2×15 mL) and H2O (2×15 mL)
8. 8
   SéchageThe organic phase was dried over anhydrous Na2SO4
9. 9
   Autreevaporated under reduced pressure

Mode opératoire

The starting amine (5) (0.15 g, 0.12 mmol) and fluorescein isothiocyanate (FLITC) (0.056 g, 0.14 mmol) were dissolved in a mixture of DMF and CH2Cl2 (6 mL, 1:5 ratio) at room temperature. The reaction was cooled to 0° C., and then an excess amount of Et3N (66 μL, 0.48 mmol) was added dropwise. An orange colored precipitate was immediately formed and remained during the entire period of the reaction. After completion of the reaction, the insoluble precipitate was filtered off; and the solvent was removed under reduced pressure. The residue was diluted with CH2Cl2 (15 mL), washed with 1N HCl (2×15 mL) and H2O (2×15 mL). The organic phase was dried over anhydrous Na2SO4 and evaporated under reduced pressure to afford 0.18 g (92%) of fluorescein-labeled guanidine (17) as an orange colored foam-shaped solid. 1H NMR (CD3OD): δ 8.20 (s, 1H, ArH), 7.86 (m, 1H, ArH), 7.22 (m, 2H, ArH), 6.64 (m, 3H, ArH), 6.56 (m, 2H, ArH), 3.86 (m, 2H, CH2NHCS), 3.66 (m, 12H, CH2O), 3.46 (m, 6H, CH2NHCO), 3.38 (m, 6H, CH2NH), 2.58 (m, 2H, CH2CO), 2.42 (m, 6H, CH2CO), 1.48 (s, 27H, t-Bu), 1.46 (s, 27H, t-Bu).

Source