反应详情

A suspension of 1H-benzotriazole-5-carboxylic acid in ethanol (50 ml, excess) was gently refluxed overnight in the presence of conc. sulphuric acid (0.5 ml), by which time TLC (A) indicated complete reaction. Ethanol was removed in vacuo to afford an aqueous residue that was dissolved in ethyl acetate (30 ml) and extracted with sodium chloride solution (4×20 ml). The organic layer was dried over sodium sulphate and removal of solvent in vacuo afforded the pure ester [24] in 86% yield. Rf (A) 0.75; δH(400 MHz; DMSO-d6) 1.36 (3H, t, CH3) 4.36 (2H, q, CH2) 7.94 (2H, br s, BT) 8.59 (1H, br s, BT) 16.03 (1H, s, NH); m/z (EI−HR) 191.07023 [(M) calc. for C9H9N3O2 191.06948].

1. customreaction
2. customEthanol was removed in vacuo
3. customto afford an aqueous residue that
4. extractionextracted with sodium chloride solution (4×20 ml)
5. dry with materialThe organic layer was dried over sodium sulphate and removal of solvent in vacuo