Abstract
A series of 5-aryl-5,8-dihydrotetrazolo[1,5-a]pyrimidine-7-carboxylic acids (4) were synthesized from 5-aminotetrazole, pyruvic acid, and aromatic aldehydes in one pot in the presence of I2 with moderate to good yields. Operational simplicity, mild reaction conditions, and ecofriendly procedure make this novel protocol a promising alternative for the fusion of tetrazolopyrimidines. The structures of the products were proved by 1H and 13C NMR spectroscopy, liquid chromatography–mass spectrometry, and elemental analysis.
Notes
a Reaction conditions:1 (2 mmol), 4-bromobenzaldehyde (2 mmol), 2 (2 mmol), I2 (0.4 mmol), solvent 2 mL.
b Isolated yield.
c Reaction was conducted without iodine.
d The reaction mixture was solidified in 10 min without solvent.
e 20 mol% of Et3N was added.
f n(5-AT):n(4-bromobenzaldehyde):n(pyruvic acid) = 1.2:1:1.
a Reaction conditions: 1 (2 mmol), 4-bromobenzaldehyde (2 mmol), 2 (2 mmol), solvent 2 mL, and refluxing temperature.
b Isolated yield.
a Reaction conditions: 1 (2 mmol), 2 (2 mmol), aromatic benzaldehyde (2 mmol), AcOEt (2 mL), I2 (0.3 mmol, 15 mol%), and temperature (78 °C).
b Isolated yield.