4-Chlorobenzaldehyde → 4-acetyl-5-(4-chlorophenyl)-1-(3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-yl)-3-hydroxy-1H-pyrrol-2(5H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 3,8-dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-amine (Step 67.4) (2 g, 12.33 mmol), 4-chlorobenzaldehyde (1.576 g, 11.21 mmol) and ethyl 2,4-dioxopentanoate (1.773 g, 11.21 mmol) in acetic acid (10 mL) was stirred for 2 hr at 100° C. The reaction mixture was concentrated, diluted with CH2Cl2/1N NaOH and extracted with CH2Cl2. The combined organic layers were dried over Na2SO4, evaporated and discarded as they contained no desired product. The aqueous was acidified to pH 3 with 6N HCl and extracted with CH2Cl2. The combined organic extracts were dried over Na2SO4 and concentrated to afford the title compound (3.88 g, 8.80 mmol, 79% yield) as a beige foam. tR: 0.70 min (LC-MS 2); ESI-MS: 397 [M+H]+ (LC-MS 2); 1H NMR (400 MHz, DMSO-d6) δ ppm 2.36 (s, 3H) 2.44 (s, 3H) 2.63 (s, 3H) 6.14 (s, 1H) 7.27 (d, J=8.44 Hz, 2H) 7.33-7.40 (m, 3H) 8.53 (s, 1H).

Provenance & Evidence