1,2-Dichloroethane → 3-Hydroxy-2-{2-[5-(2-methyl-[1,3]dioxolan-2-yl)-thiophen-2-yl]-acetylamino}-propionic acid methyl ester

Participants

Reaction Steps

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of [5-(2-methyl-[1,3]dioxolan-2-yl)-thiophen-2-yl]-acetic acid (1.25 g, 5.48 mmol) in CH2Cl2 (20 mL) was treated sequentially with DMAP (135 mg, 1.10 mmol), HOBT (1.07 g, 6.80 mmol), EDC (2.68 g, 13.69 mmol) and DIPEA (3.85 mL, 21.9 mmol). After stirring for 1 h at rt, serine methylester hydrochloride (913 g, 5.75 mmol was added and the reaction mixture stirred for 1 h at rt. Sat. aq. NH4Cl was added and the mixture was extracted twice with CH2Cl2. The combined org. extracts were dried over Na2SO4, filtered, and the solvent was removed under reduced pressure. Purification of the residue by FC (1000:25:2 CH2Cl2-MeOH—NH4OH) gave the title compound as an orange oil. TLC: rf (EA)=0.3. LC-MS-conditions 01: tR=0.68 min; [M+H]+=329.94.

Provenance & Evidence