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

Temperatur

-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-Eintrag

ord-cd1494d8fc6a406eba7a47872be515f3

Quelldatensatz

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09394311B2