Reaction #1442503

Reaction equation

Fmoc-Osu

Amino acid

4-(2-Aminoethoxy)-2-hydroxybenzoic acid, hydrochloride

acetone water

Sodium Carbonate

→

4-[(2-fluorenylmethyloxycarbonylamino)ethoxy]-2-hydroxybenzoic acid

Solvents

acetone

Conditions

Workup

1. 1
   ConcentrationThe reaction mixture was concentrated
2. 2
   workup.DISSOLUTIONthe residue was dissolved in water
3. 3
   Extractionextracted with ether (2×50 mL)
4. 4
   TemperatureThe aqueous layer was cooled in an ice bath
5. 5
   OtherThe solid obtained
6. 6
   Filtrationwas filtered
7. 7
   Washwashed with water
8. 8
   Otherdried under vacuo (3.22 g)

Procedure

The Amino acid (14) (1.864 g; 8 mmol) from Step 2 was dissolved in 1:1 acetone—water (50 mL) containing Sodium Carbonate (1.696 g; 16 mmol). To the solution was added Fmoc-Osu (2.696 g; 8 mmol) in acetone (25 mL) dropwise at room temperature. The solution was stirred at room temperature for 18 h. The reaction mixture was concentrated and the residue was dissolved in water and extracted with ether (2×50 mL). The aqueous layer was cooled in an ice bath and acidified with 6N HCl to pH 3. The solid obtained was filtered and washed with water and dried under vacuo (3.22 g). NMR (300 MHz, DMSO-d6) δ7.9 (d, 2H), 7.65-7.75 (m, 2H), 7.55 (t, 2H), 7.4 (t, 2H), 7.3 (t, 2H), 6.5 (m, 2H), 4.35 (d, 2H), 4.25 (t, 1H), 4.05 (t, 2H), 3.4 (t, 2H).

Source