Next Article in Journal
Previous Article in Journal

Molbank 2003, 2003(1), M307;

Short Note
Department of Chemistry, Faculty of Science, United Arab Emirates University, P.O.Box 17551 Al-Ain, UAE
Author to whom correspondence should be addressed.
Received: 16 June 2002 / Accepted: 30 September 2002 / Published: 11 March 2003
Ribofuranose; Nucleosides; Dihydropyrazol-3-one
Molbank 2003 m307 i001
The desired compound 2 was obtained by complete deprotection of the acetylated nucleoside 1 [1] using triethylamine [2]. To a solution of 1 (0.8g, 1.5 mmol) in methanol (25 ml) was added triethylamine (2 ml). The mixture was stirred at room temperature and the reaction was followed by tlc. After complete deprotection (24 hours), the reaction mixture was evaporated and coevaporated with methanol (3 x 30 ml), then chromatographed over silica gel using CH2Cl2/MeOH (95:5 v/v) to give 0.55 g (90%) of 2 as yellow powder.
Rf: 0.30 (CH2Cl2/MeOH, 95/5 v/v).
UV (lmax , 95% ethanol): 384nm
IR (KBr, cm-1): 3414 (OH), 1662 (CO pyrazolone).
MS (m/z): 402.
1H-NMR (250 MHz, DMSO-d6): 2.38(s, 3H, CH3); 2.40(s, 1H, CH); 3.73(dd, 1H, H-5` J5`,4`=2.4 Hz) 3.91-3.96(dd, 1H, H-5`` J5``,4`=2.4 Hz); 4.23-4.24(m, 1H, H-4`); 4.53(t, 1H, H-3` J3`,2`=3.66 Hz); 4.75(t, 1H, H-2` J2`,3`=5.13 Hz); 5.94(d, 1H, H-1`, J1`,2`=4.92 Hz); 7.21-7.37(m, 4H, aromatic CH).
13C-NMR (75 MHz, DMSO-d6): 22.0(CH3); 48.9(CH); 63.08(C-5`), 71.71(C-3`); 73.90(C-2`); 85.63(C-4`); 88.08(C-1`); 116.9 (2 aromatic carbons), 121.0, 122.0 (2 aromatic carbons), 130.4, 144.0 (2 quaternary aromatic carbons); 137.7(q, CF3); 148.5(C=N); 173.5(CO).

Supplementary materials

Supplementary File 1Supplementary File 2Supplementary File 3

References and Notes

  1. Haikal, A.; Zohdi, H. F.; Badi, Z. Molbank 2003, M0306.
  2. Zohdi, H. F.; Haikal, A. Molecules 2001, 6, M263.
Back to TopTop