3,7-diethyl-3,7-dimethyl-4,6-Nonanedione

3,7-diethyl-3,7-dimethyl-4,6-Nonanedione, also known as 2,2,6,6-tetraethyl-3,5-heptanedione, is a light yellow transparent liquid.

3,7-diethyl-3,7-dimethyl-4,6-Nonanedione could replace alkoxide ligands leads to the formation of the thermodynamically stable Zr(thd)4. Modification with 2,2,6,6,- tetramethyl-3,5-heptanedione (Hthd) provides higher volatility by the improved shielding effect on the metal atom by the larger terminal organic groups[1].

Under nitrogen protection, N,N'-dimethoxy-N,N'-dimethylmalonamide (76.1g, 0.4mol), B(C6F5)3(20.5g ,0.04mol), and 380mL 2-methyltetrahydrofuran were added to reaction vial. Lower the temperature to -20°C, 587mL 1.5mol/L 3-methyl pentane magnesium chloride 2-methyl tetrahydrofuran solution (0.88mol) was added dropwise at this temperature and then slowly raise the temperature to 0°C. React for 1 hour, add dropwise saturated ammonium chloride aqueous solution to quench and extract the aqueous phase with ethyl acetate, combine the organic phases and concentrate, heat up and vacuum rectify under reduced pressure. Finally, collect fractions at 145-152°C to obtain 3,7-diethyl-3,7-dimethyl-4,6-Nonanedione.

[1] Spijksma G, et al. Chemistry of 2,2,6,6,-Tetramethyl-3,5-heptanedione (Hthd) Modification of Zirconium and Hafnium Propoxide Precursors. Inorg. Chem., 2006; 45: 4938–4950.