Acetic acid, 2,2'-[1,3-propanediylbis(oxy)]bis-, diethyl ester (9CI) synthesis

Yield:77319-28-9 61%

Reaction Conditions:

with rhodium(II) acetate in dichloromethane at 10; for 16 h;

Steps:

1 Step 1-Ethyl 2-[3-(2-ethoxy-2-oxo-ethoxy)propoxy]acetate

To a solution of propane-1,3-diol (15.0 g, 197 mmol, CAS126-30-7) and Rh(OAc)₂ (435 mg, 1.97 mmol) in DCM (200 mL) was added a solution of ethyl 2-diazoacetate (67.4 g, 591 mmol) in DCM (100 mL) dropwise. The mixture was stirred at 10° C. for 16 hours. On completion, the mixture was diluted with H₂O (150 mL) and extracted with DCM (3×150 mL). The combined organic layers were dried over Na₂SO₄, filtered and concentrated in vacuo to give a residue. The residue was purified by column chromatography (SiO₂) to give the title compound (30.0 g, 61% yield) as colorless liquid. ¹H NMR (400 MHz, CDCl₃) δ 4.21 (q, J=7.2 Hz, 4H), 4.07 (s, 4H), 3.65 (t, J=6.4 Hz, 4H), 1.99-1.89 (m, 2H), 1.28 (t, J=7.2 Hz, 6H).

References:

US2019/192668,2019,A1 Location in patent:Paragraph 3132; 3133