Sodium Carbonate → HCID 20040881, compound

Participants

Reaction Steps

A solution of 3-amino-7-chloro-5-methyl-1H-pyrazolo[4,3-b]pyridine (D7) (0.5 g) in water (13.5 ml) and concentrated sulphuric acid (2 ml) was treated at 0° with a solution of sodium nitrite (0.406 g) in water (2 ml) added dropwise with stirring. On completion of the addition the mixture was stirred at 0° for 20 min before bringing to pH 8 with saturated sodium carbonate. The resulting solid was collected and dried (0.18 g). The filtrate was extracted with chloroform (3×50 ml), the combined extracts dried with magnesium sulphate, filtered and evaporated to dryness to give a yellow solid which was combined with the solid originally collected, m.p. 119°-124° (combined yield 0.5 g). This crude material was recrystallised from cyclohexane to give the title compound as yellow needles (0.358 g, 68%), m.p. 123.5°-125° (decomposition). (Found: C, 43.51; H, 1.88; N, 35.79; Cl, 18.68. C7H4ClN5 requires C, 43.43; H, 2.08; N, 36.17; Cl, 18.31%). Found M+ 193.0154, C7H4ClN5 requires 193.0155.

Provenance & Evidence