Preparation and catalytic hydrogenation of 1,2,4-oxadiazolo[4,5-a]indolines

Article abstract of DOI:10.1016/S0040-4020(01)90084-5

2,3,3-Trimethyl-3H-indole 1 reacts with nitrile oxides 2 to afford 1,2,4-oxadiazolo [4,5-a]indolines 3 in high yields. Catalytic hydrogenation of compounds 3 over Raney nicke results in the cleavage of the oxadiazole ring and gives almost quantitatively products 4 or 5.