Hantzsch ester → 2-Pyridin-2-yl-1,2,3,4-tetrahydroquinoline

Participants

Reaction Conditions

Reaction Steps

A suspension of 2-pyridin-2-ylquinoline (0.767 g, 3.72 mmol), 1,4-dihydro-3,5-dicarbethoxy-2,6-dimethylpyridine (2.17 g, 8.55 mmol), and diphenyl hydrogen phosphate (0.0093 g, 0.037 mmol) in benzene (18.6 mL) was heated at 60° C. for 10 h. The reaction mixture was treated with 2-phenylquinoline (0.305 g, 1.49 mmol) and heated at 60° C. for 3 h. The reaction mixture was then concentrated to a crude solid. Purification by flash column chromatography (100% hexanes to 50% ethyl acetate/hexanes [the ethyl acetate contained 5% methanol]) gave the desired product (0.735 g, 94%) as a racemic mixture. LCMS calculated for C14H15N2 (M+H)+: m/z=211.1. found: 211.1.

Provenance & Evidence