3-bromo-2-(hydroxymethyl)-6-methyl-4H-pyrido[1,2-a]pyrimidin-4-one → 3-bromo-6-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-2-carbaldehyde

Participants

Reaction Steps

A mixture of 3-bromo-2-(hydroxymethyl)-6-methyl-4H-pyrido[1,2-a]pyrimidin-4-one (2.7421 g, 10.19 mmol, Prepared in Example 1) and manganese(IV) oxide (8.86 g, 102 mmol) in toluene (67.9 mL) was heated to reflux. After 3 h, the mixture was cooled to rt and filtered through a pad of Celite™, The filtrate was concd under reduced pressure to give 3-bromo-6-methyl-4-oxo-4H-pyrido[1,2-a]-pyrimidine-2-carbaldehyde as a bright yellow solid: 1H NMR (400 MHz, DMSO-d6) δ ppm 10.07 (1 H, s), 7.81 (1 H, dd, J=9.0, 7.0 Hz), 7.60 (1 H, dd, J=9.0, 0.8 Hz), 7.10-7.15 (1 H, m), 2.96 (3 H, s); Mass Spectrum (ESI) m/e=267.0 [M+1 (79Br)] and 268.9 [M+1 (81Br)].

Provenance & Evidence