反应详情

A mixture of 1,1,3,3-tetramethoxypropane (13.6 g, 83 mmol) and N2-cyclopentyl-N1-(tert-butoxycarbonyl)hydrazine (16.6 g, 83 mmol, see Ranatunge et al., J. Med. Chem. (2004), 47, p2180-2193) in water (150 mL) was treated with cone. HCl (21 mL, 252 mmol). The resulting mixture was heated at reflux overnight. The completed reaction mixture was extracted with ether and the extracts were washed with brine, dried over anhydrous MgSO4, and concentrated in vacuo to give 1-cyclopentyl-1 H-pyrazole (8.0 g, 71% yield. 1H NMR (400 MHz, CDCl3): δ 7.52 (s, 1 H), 7.43 (s, 1 H), 6.24 (s, 1 H), 4.68 (m, 1 H), 2.20-1.71 (m, 8 H). MS (ESI) m/z; 137.1 [M+H+].

1. additionwas treated with cone
2. temperatureThe resulting mixture was heated
3. temperatureat reflux overnight
4. customThe completed reaction mixture
5. extractionwas extracted with ether
6. washthe extracts were washed with brine
7. dry with materialdried over anhydrous MgSO4
8. concentrationconcentrated in vacuo