Triphenylphosphine → 1,4-Dihydrocinnoline

Participants

Reaction Steps

510 mg of a mixture of (cinnolin-4-yl)-methanol and (1,4-dihydro-cinnolin-4-yl)-methanol (see Ex. XXVII) are added to 830 mg of 3-methyl-7-(3-methyl-2-buten-1-yl)-8-chloro-xanthine and 1.25 g of triphenylphosphine in 25 ml of tetrahydrofuran. The reaction mixture is combined with 0.92 ml diethyl azodicarboxylate and stirred overnight at ambient temperature. Then it is evaporated down and chromatographed through a silica gel column with ethyl acetate/petroleum ether (7:3 to 0:1) as eluant. A mixture of cinnoline and 1,4-dihydro-cinnoline compound is obtained.

Provenance & Evidence