تفاعل #1724967

معادلة التفاعل

6-Acetyl-2-chloro-3-hydroxy-4-iodo-pyridine

triethylamine

trimethylsilyl acetylene

→

6-acetyl-2-chloro-3-hydroxy-4-(2-trimethylsilylethynyl)pyridine

المردود 88.5%

المذيبات

chloroform tetrahydrofuran

ethyl acetate

ظروف التفاعل

المعالجة

1. 1
   غسيلwas washed with 2×50 ml of 5% hydrochloric acid
2. 2
   تجفيفThe organics were dried over anhydrous magnesium sulfate
3. 3
   workup.ADDITIONtreated with 10 g of silica gel (230-400 mesh)
4. 4
   تركيزconcentrated to dryness
5. 5
   أخرىThe plug was chromatographed over 200 g of silica gel (230-400 mesh)
6. 6
   غسيلeluting with 25% ethyl acetate/hexane+0.1% acetic acid
7. 7
   أخرىwhile collecting 50 ml fractions
8. 8
   تركيزconcentrated

الإجراء التجريبي

6-Acetyl-2-chloro-3-hydroxy-4-iodo-pyridine (6.12 g, 20.6 mmole) was combined with trimethylsilyl acetylene (3.5 ml, 24.7 mmole), bis (triphenylphosphine) palladium dichloride (730 mg, 10 mmole) and cuprous iodide (99 mg, 0.52 mmole) in 37 ml of 2:1 chloroform/tetrahydrofuran in a 100 ml one neck round bottom flask under nitrogen. The suspension was treated with triethylamine (6 ml, 43 mmole) and the reaction was stirred for 2 h at room temperature. The mixture was diluted with 150 ml of ethyl acetate and was washed with 2×50 ml of 5% hydrochloric acid. The organics were dried over anhydrous magnesium sulfate, treated with 10 g of silica gel (230-400 mesh), and concentrated to dryness. The plug was chromatographed over 200 g of silica gel (230-400 mesh), eluting with 25% ethyl acetate/hexane+0.1% acetic acid, while collecting 50 ml fractions. Fractions 10-18 were combined and concentrated to give 4.88 g (88%) of 6-acetyl-2-chloro-3-hydroxy-4-(2-trimethylsilylethynyl)pyridine as a pale tan solid. 1H NMR (d6DMSO): δ 8 0.26 (s, 9), 2.51 (s, 3), 7.78 (s, 1) ppm.

المصدر