Tetrahydrofuran → HCID 66632564, compound

Participants

Reaction Conditions

Reaction Steps

4-(7,8-Dimethoxy-3H-pyrazolo[3,4-c]quinolin-1-yl)-2-vinylbenzonitrile (247 mg, 693 μmol) is dissolved in N,N-dimethylformamide (1.5 ml), tetrahydrofuran (6.0 ml) and ethanol (9.0 ml) and cooled to (−) 78° C. The reaction solution is subsequently treated with ozone (oxygen flow of ozone generator 50 l/h) for 4 min, nitrogen is then passed through (2 min). After LC-MS check (aldehyde intermediate), NaBH4 (24 mg, 624 μmol) is added, and the reaction mixture is stirred at (−)78° C. for 20 min. The cold bath is subsequently removed, so that the reaction solution warms to room temperature. For purification, the mixture is extracted with ethyl acetate and semi-saturated sodium chloride solution. The organic phase is dried over Na2SO4, filtered with suction and evaporated to dryness at 40° C. in vacuo. The residue is purified by chromatography (pHPLC, solvent gradient water/1-30% by vol. of acetonitrile, 0.1% by vol. of formic acid), and the product fractions are lyophilised, giving 4-(7,8-dimethoxy-3H-pyrazolo[3,4-c]quinolin-1-yl)-2-hydroxymethylbenzonitrile (46 mg, 128 μmol) as a solid. MS: 361.4 (M+H+), TLC (HPTLC): Rf=0.38 (ethyl acetate/ethanol 8:1, parts by volume).

Provenance & Evidence