Water → HCID 21853340, compound

HRID 838872Notes

Reaction equation

HRID 838872 reaction equation
[C:1]([NH:4][C:5]1[S:9][N:8]([C@@H:10]2[O:22][C@H:21]([CH2:23][O:24]C(=O)C)[C@@H:16]([O:17]C(=O)C)[C@H:11]2[O:12]C(=O)C)[C:7](=[O:28])[N:6]=1)(=[O:3])[CH3:2].C[O-].[Na+].O>CO>[C:1]([NH:4][C:5]1[S:9][N:8]([C@@H:10]2[O:22][C@H:21]([CH2:23][OH:24])[C@@H:16]([OH:17])[C@H:11]2[OH:12])[C:7](=[O:28])[N:6]=1)(=[O:3])[CH3:2]

Participants

5

Reactant 3

HCID 962WaterHCID 10942334Sodium MethoxideHCID 21853337HCID 21853337, compound

Product 1

HCID 21853340HCID 21853340, compound

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

To a solution of 5-acetamido-2-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-1,2,4-thiadiazol-3-one (4, 0.5 g, 0.0011 mole) in anhydrous methanol (25 ml) was added 1N sodium methoxide in methanol, till the pH of the solution was 8.5 and the resulting solution was stirred at ambient temperature for 2.5 hr. Within 40 min the secondary O-acetyl groups were removed and by the end of 2 hr all the O-acetyl groups were removed as judged by tlc. After the O-deacetylation was complete, the sodium ions were removed by stirring the reaction mixture with Amberlite IRC-50 (H+) resin (7.0 g, dry weight) for 15 min before the neutral solution, free from resin, was evaporated to dryness. The residual gum was chromatographed on a silica gel column (3 × 27 cms) using ethyl acetate:water:n-propanol (4:2:1), v/v, upper phase). The appropriate fractions were pooled, solvent evaporated and the residue crystallized from aqueous ethanol to yield 0.23 g (67.0%), m.p. 204°-205° (dec.); [α]D25 -50.1° (c 1.0, water); 1H nmr (Me2SO-d6) δ2.28 (s, 3H, --NAc), 5.65 (d, J=5.0 Hz, C1'H); uv λmax (pH 1) 235 nm (ε 10,600), 275 (3500); λmax (pH 7) 254 nm (ε 9900), 277 sh (5400); λmax (pH 11) 254 nm (ε 12,700), 277 sh (5,900).

Workup

  1. customWithin 40 min the secondary O-acetyl groups were removed and by the end of 2 hr all the O-acetyl groups
  2. customwere removed
  3. customthe sodium ions were removed
  4. stirringby stirring the reaction mixture
  5. customwith Amberlite IRC-50 (H+) resin (7.0 g, dry weight) for 15 min before the neutral solution
  6. customfree from resin, was evaporated to dryness
  7. customThe residual gum was chromatographed on a silica gel column (3 × 27 cms)
  8. customsolvent evaporated
  9. customthe residue crystallized from aqueous ethanol
  10. customto yield 0.23 g (67.0%), m.p. 204°-205° (dec.)

Sources & evidence

ORD record
ord-0f5bfbc346694dd09b1c0a13fa9c5ced
Source dataset
uspto-grants-1978_06
Patent number
US04093624

Reaction notes

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