Synthesis and study of some 4-substituted 2-(benzimidazol-2?-yl)quinolines

Quinoline Aldehydes

“…No free aldehydes were isolated, but when compound 113b was added to oxalic acid in ethanol it gave the expected pyridazinoquinoline directly.R=NH2, b p 165 -168 OC/0.06 mrn2. Quinoline Aldehydes with Partially Saturated Benzene RingsThe ester114 was converted in three steps to the aldehyde 1 rn.p 217-219 OC The ester 116a was reduced (LAH) and re-oxidized (CrO,, Py) to the aldehyde 116b.48%, m.p. 77 O C The nitrile 11% was reduced with DIBAH and hydrolysed with aqueous acid to give the aldehyde 119b.338 The side-chain aldehyde 120 was made in an exactly similar way.339 119 a , R=CN b , R-CHO, 8 8 % , oil 120,45.5%, b.p.…”