Ammonia → 5-(Benzoxazol-2-yl)-2-methyl-1-(tetrahydropyran-4-yl)benzimidazole

Participants

Reaction Conditions

Reaction Steps

An eggplant flask (100 mL) was charged with 2-methyl-1-(tetrahydropyran-4-yl)benzimidazole-5-carboxylic acid HCl salt (see Working Example 4-3) (0.64 g, 2.46 mmol), 2-aminophenol (0.32 g, 2.95 mmol) and polyphosphoric acid (approx. 18 g), and this was heated to 160° C. and stirred for 17 hours. After being allowed to cool, ice was added and concentrated aqueous ammonia (28%) was added to the liquid to give approx. pH 9. This was extracted with chloroform (approx. 50 mL, 3 times) and dried over anhydrous magnesium sulfate. The crude product (0.08 g) obtained after the solvent was distilled off was purified by PTLC (CHCl3) with double development to yield the title compound (0.002 g, 0.2% yield) as a yellowish-brown semisolid.

Provenance & Evidence