Dimethylformamide → 5-(4-bromo-1H-imidazol-1-yl)-1,6-naphthyridin-2(1H)-one

Participants

Reaction Steps

A stirred mixture containing 11.25 g of 5-bromo-1,6-naphthyridin-2(1H)-one, 16.6 g of 4-bromo-1H-imidazole and 100 ml of N-methylpyrrolidinone was heated in an oil bath at 135°-140° C. for 22 hours. The reaction mixture was cooled and diluted with 200 ml of water. The resulting precipitate was collected, washed with water, air-dried, combined with 1.5 g of 5-(4-bromo-1H-imidazol-1-yl)-1,6-naphthyridin-2(1H)-one prepared in another run starting with 1 58 g of 5-bromo-1,6-naphthyridin-2(1H)-one, recrystallized twice from dimethylformamide and dried in an Abderhalden drying pistol at 90° for 22 hours, after which the sample still contained 0.2 mol of dimethylformamide per mol of product. The material was then dissolved in 100 ml of 5% aqueous sodium hydroxide solution, the solution filtered and the filtrate solidified with acetic acid. The cottony solid that crystallized out was collected, washed with distilled water and dried in an oven at 100° C. over the weekend to produce 10.3 g of 5-(4-bromo-1H-imidazol-1-yl)- 1,6-naphthyridin-2(1H)-one, m.p. 278°-280° C.

Provenance & Evidence