INTRODUCTION Coumarin derivatives have been used widely for the treatment of a numberous diseases such as heart disease 1-3 , lymphoedema and other high-protein edemas 4 . They have also found pharmaceutical applications in the treatment of patients with chronic venous insufficiency 5 , skin cancer 6 , renal cell carcinoma 7 , prostate cancer 8 as well as in the treatment of thermal injuries 9 . They may also be useful in preventing oxidative stress and apoptosis in HIV infection 10 . Thiosemicarbazides exhibit various biological activities and are extensively applied in medicine, particularly in the treatment of tuberculosis 11,12 . Numerous compounds with a thiosemicarbazone moiety also exhibit biological activity 13,14 . Several peracetylated glycopyranosyl thiosemicarbazones were synthesized 15,16 . Some peracetylated glycopyranosyl thiosemicarbazones containing coumarin ring were synthesized in good yields by the reactions of substituted 3-acetylcoumarins with 4-(tetra-O-acetyl-β-D-glucopyranosyl) thiosemicarbazide in our lab 17 . Continuing our works on glycopyranosyl thiosemicarbazones 18-20 , we reported herein the synthesis of some substituted 4-formylcoumarin 4-(tetra-O-acetyl-β-D- glucopyranosyl)thiosemicarbazones. EXPERIMENTAL All solvents and reagents were purchased from Merck (Vietnam). Melting points were determined by open capillary method on STUART SMP3 instrument (BIBBY STERILIN- UK) and are uncorrected. IR spectra (KBr disc) were recorded on a Impact 410 FT-IR Spectrometer (Nicolet, USA). 1 H and Synthesis of Some Peracetylated Glucopyranosyl Thiosemicarbazones of Substituted 4-Formylcoumarins NGUYEN DINH THANH * and VU NGOC TOAN Faculty of Chemistry, College of Science, Hanoi National University, 19 Le Thanh Tong, Hanoi 10000, Vietnam *Corresponding author: Fax: +84 4 38241140; Tel: +84 4 38261853; E-mail: nguyendinhthanh@hus.edu.vn (Received: 31 July 2012; Accepted: 22 May 2013) AJC-13531 Some substituted 4-formylcoumarins were prepared by oxidation of 4-corresponding formylcoumarins using SeO2. These aldehydes were converted to thiosemicarbazones by condensation reaction with tetra-O-acetyl-β-D-glucopyranosyl thiosemicarbazide usingmicrowave- assisted heating method. The synthesized compounds were characterized by FT-IR and 1 H NMR, 13 C NMR and mass spectral studies. Key Words: Thiosemicarbazide, Glucopyranose, Thiosemicarbazones, Microwave-assisted, 4-Formylcoumarin. Asian Journal of Chemistry; Vol. 25, No. 12 (2013), 6609-6611 13 C NMR spectra were recorded on Bruker Avance spectro- meter AV500 (Bruker, Germany) at 500.13 MHz and 125.77 MHz, respectively, using DMSO-d6 as solvent and TMS as an internal standard. MS spectra were recorded on mass spectro- meter LTQ Orbitrap XL TM (Thermo Scientific, USA) using ESI method. All the starting benzaldehydes were purchased from commercial suppliers (Merck-Germany) and used with no further purification. All other solvents and reagents were used as received or purified by standard protocols. 4-(Tetra- O-acetyl-β-glucopyranosyl)thiosemicarbazide were prepared from tetra-O-acetyl-β-glucopyranosyl isothiocyanate 16 . 4- Formyl-6-(or 7-)-methyl/alkoxy-4-formylcoumarins were synthesized based on the synthetic method for 4-formyl-7- methoxylcoumarin 21 . Synthesis of thiosemicarbazones (4a-f): To a solution of 4-(tetra-O-acetyl-β-D-glucopyranosyl)thiosemicarbazide (1 mmol) in 99 % ethanol (10 mL) substituted 4-formylcoumarin 3 (1 mmol) was added. Glacial acetic acid (0.5 mL) as catalyst was added dropwise with stirring. The obtained mixture was then irradiated in microwave oven for 9-13 min, cool to room temperature, the separated precipitate was filted and recrysta- llized from 96 % ethanol to yield the title compounds 4. 4-Formyl-7-methylcoumarin 4-(2,3,4,6-tetra-O-acetyl- β-D-glucopyranosyl)thiosemicarbazone (4a): Yellow solid, m.p. 150-152 ºC, yield 65 %; IR (KBr, νmax, cm -1 ): 3456, 3259, 1747, 1720, 1617, 1528, 1500, 1490, 1211, 1044, 1090; 1 H NMR (DMSO-d6) d (ppm): 8.47 (s, 1H, CH=N), 12.23 (s, 1H, NH-2), 9.12 (d, 1H, J = 9.5 Hz, NH-4), 6., 00 (t, 1H, J = 9.25 Hz, H-1'), 5.34 (t, 1H, J = 9.25 Hz, H-2'), 5.43 (t, 1H, J = 9.5 Hz, H-3'), 4.98 (t, 1H, J = 9.75 Hz, H-4'), 4.23 (dd, 1H, J = http://dx.doi.org/10.14233/ajchem.2013.14385