Uses
Glyoxal dimethyl acetal is an important raw material and intermediate used in organic synthesis, pharmaceuticals agrochemicals and dyestuffs.
General Description
This product is a 60wt% solution of 2,2-dimethoxyacetaldehyde (glyoxal dimethyl acetal) in water. The aldol condensation of 2,2-dimethoxyacetaldehyde with acetoacetic ester in the absence of the catalyst and solvent has been reported. It participates in the synthesis of isoxazoline vinyl ester pseudopeptides and tetrahydro-β-carboline derivatives of barbituric acid analogs.
Synthesis
NaIO4 (3 g, 14 mmol) was added to a suspension of DCM (30 mL) containing silica (10 g), followed by the addition of olefin 9 (355 mg, 2 mmol) pre-dissolved in DCM (20 mL). The reaction mixture was stirred at room temperature for 30 min and then filtered. The solid residue was washed twice with DCM (20 mL). The combined organic phases were dried with MgSO4, filtered and concentrated under reduced pressure under strictly controlled conditions (20 °C, 300 mmHg) to avoid loss of aldehyde 10 due to high volatility. A clear liquid-like crude product (350 mg, 85% yield) was finally obtained, which was directly used in the subsequent reaction without further purification.1H NMR (400 MHz, CDCl3): δ= 9.47 (d, J = 1.5 Hz, 1H, 1-H), 4.50 (d, J = 1.5 Hz, 1H, 2-H), 3.46 (s, 6H, 3-H) ppm. 13C NMR (100 MHz, CDCl3): δ= 199.2 (1-C), 122.3 (2-C), 54.6 (3-C) ppm.
References
[1] Tetrahedron Asymmetry, 2013, vol. 24, # 18, p. 1175 - 1181
[2] Patent: CN105753834, 2016, A. Location in patent: Paragraph 0040; 0041; 0042
[3] Patent: CN105153110, 2017, B. Location in patent: Paragraph 0034-0036
