Sodium ethoxide → HCID 54008737, compound

Participants

Reaction Steps

The crude ethyl-(2′,3′,5′-tri-O benzoyl-β-D-ribofiuranosyl)thiazole-4-carboxylate (4, 15.00 g) was dissolved in dry ethanol (100 ml) and treated with sodium ethoxide powder (1.36 g, 20 mmol) under argon atmosphere. The reaction mixture was stirred at room temperature for 12 hr under argon. The solution was neutralized with Dowex 50W-X8 H+ resin, filtered and washed with methanol (100 ml). The filtrate was evaporated to dryness. The residue was partitioned between water (100 ml) and chloroform (I50 ml). The aqueous layer was washed with chloroform (100 ml) and evaporated to dryness. The residue was dissolved in methanol (100 ml), silica gel (15 g) was added and evaporated to dryness. The dried compound adsorbed silica gel was placed on top of the silica column (5×20 cm) packed in CH2Cl2. The column was eluted with CH2Cl2/acetone (7:3; 500 ml) followed by CH2Cl2/methanol(95:5; 1000 ml). The CH2 C12/methanol fractions were collected together and evaporated to give pure 5. A small amount was crystallized from 2-propanol/ether as colorless product. Yield 4.8 g (83%); mp 62-64° C. 1H NMR (DMSO-d6); δ 1.36 (t, 3 H), 3.52 (m; 2 H), 3.84 (m, 2 H), 4.06 (m, I H), 4.28 (m, 2 H), 4.94 (t, 1H), 4.98 (d, 1 H), 5.08 (d, I H), 5.46 (d, I H) and 8.52 (s, 1 H).

Provenance & Evidence