반응 #799257

반응 방정식

1,1-dimethoxy-N,N-dimethylmethanamine

tert-butyl [2-(5-methyl-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrazol-3-yl)-3-thienyl]carbamate

trifluoroacetic acid

→

desired product

8-Methylpyrazolo[1,5-c]thieno[2,3-e]pyrimidine

용매

methylene chloride

반응 조건

후처리

1. 1
   기타the solvent was removed
2. 2
   workup.DISSOLUTIONThe residue was dissolved in THF (40 mL)
3. 3
   온도The resulting solution was heated at 80° C. for 1 h
4. 4
   기타The solvent was removed under reduced pressure
5. 5
   기타The crude was purified with flash chromatography (
6. 6
   세척eluting with a gradient of 0-20% ethyl acetate in hexanes)

실험 절차

To a solution of tert-butyl [2-(5-methyl-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrazol-3-yl)-3-thienyl]carbamate (3.2 g, 7.8 mmol) in methylene chloride (23 mL) was added trifluoroacetic acid (23 mL). After stirring at room temperature for 5 h, the solvent was removed. The residue was dissolved in THF (40 mL) and treated with 1,1-dimethoxy-N,N-dimethylmethanamine (1.56 mL, 11.7 mmol). The resulting solution was heated at 80° C. for 1 h. The solvent was removed under reduced pressure. The crude was purified with flash chromatography (eluting with a gradient of 0-20% ethyl acetate in hexanes) to give the desired product as white solid. 1H NMR (300 MHz, CD3OD) δ 9.09 (1H, s), 7.81 (1H, d, J=5.3 Hz), 7.45 (1H, d, J=5.3 Hz), 6.60 (1H, s), 2.49 (3H, s) ppm. LCMS calculated for C9H8N3S (M+H)+: m/z=190.0. Found: 190.0.

출처