Dimethylformamide → 3-bromo-1-methyl-1H-1,2,4-triazole-5-carbaldehyde

Temperature

-45 °C

To a solution of 3,5-dibromo-1-methyl-1H-1,2,4-triazole (500 mg, 2.08 mmol, Eq: 1.00) in tetrahydrofuran (5 ml) was added dropwise at −45° C. under argon atmosphere n-butyllithium 1.6 M in hexane (1.56 ml, 2.49 mmol, Eq: 1.2). The resulting mixture was stirred for 30 minutes at −45° C. and was then cooled to −70° C. Then dimethyl formamide (197 mg, 209 μl, 2.7 mmol, Eq: 1.3) was added dropwise. After 15 minutes the cooling bath was removed and the mixture was allowed to reach 25° C. The mixture was stirred for additional 2 hours at 25° C. The mixture was poured on water and extracted twice with ethyl acetate, the organic layers were combined, washed with water and brine, dried over magnesium sulfate, filtrated and evaporated, affording 5-bromo-2-methyl-2H-[1,2,4]triazole-3-carbaldehyde (218 mg/55.3%) as an orange semi solid. MS: m/e=189 (M+H+)

1. temperaturewas then cooled to −70° C
2. customAfter 15 minutes the cooling bath was removed
3. customto reach 25° C
4. stirringThe mixture was stirred for additional 2 hours at 25° C
5. additionThe mixture was poured on water
6. extractionextracted twice with ethyl acetate
7. washwashed with water and brine
8. dry with materialdried over magnesium sulfate
9. filtrationfiltrated
10. customevaporated

ORD record

ord-cd1494d8fc6a406eba7a47872be515f3

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09394311B2