反应详情

A warm slurry of 3-(1-methylethoxy)-5-(phenylmethoxy )-N-1H-tetrazol-5-yl-benzo[b]thiophene-2carboxamide (1.9 g, 5 mmoles) and 20% palladium on carbon (0.5 g) in acetic acid (250 mls) is shaken under hydrogen (50 psig) in a Parr apparatus. After three hours additional catalyst (0.5 g) is added and the mixture shaken at ambient temperature for 15 hours. The catalyst is removed by filtration and rinsed with warm acetic acid (200 mls). The filtrate is stripped of solvent under reduced pressure and two portions (50 mls) of toluene are added to, then stripped from the residue, leaving the crystalline product. Recrystallization from methanol gave the pure 3-(1-methylethoxy)-5-hydroxy -N-lH-tetrazol-5-yl-benzo[b]thiophene-2-carboxamide (0.7 g): mp=258° C. (dec).

1. customThe catalyst is removed by filtration
2. washrinsed with warm acetic acid (200 mls)
3. additionare added to,
4. customleaving the crystalline product
5. customRecrystallization from methanol