反应详情

DL-α-aminocyclopropyl acetic acid (29.4 g.) was added with stirring to a solution of sodium hydroxide (20.9 g.) in distilled water (140 ml.). The solution became homogeneous, was cooled to ca. 5° and acetic anhydride (53 g.) was added dropwise over a period of 1.5. hr. whilst maintaining the temperature below 20°. The pH of the solution was adjusted to 3.0 after stirring for a further 0.75 hr., and was then extracted with chloroform: n-propanol, 3:1 (7×100 ml.) and the combined extracts evaporated down to give a white solid which was dried in vacuo over fresh phosphorus pentoxide. Freeze-drying of the aqueous layer and similar work-up to the above gave further product (total yield 26.0 g., 65%). A sample of the solid was recrystallised from chloroform:n-propanol:ether to give crystals of DL-α-acetamidocyclopropyl acetic acid [m.p 150°-154°, found C, 53.2; H. 7.0; N,8.7; C7H11NO3 requires C, 53.5; H, 7.0; N, 8.9 %. νmax (KBr) 3340 (NH), 1720 (CO2H) 1600 and 1550 (amide I and II) cm-1, τ](CD3)2SO]-0.46 (H, broad, CO2H), 1.87 (H,d, 6.9 Hz., NH), 6.32 (H,t, 8.0 Hz., side-chain CH), 8.18 (3H,s,methyl), 8.95 (H, broad, ring methine), 9.65 (4H, broad, complex, ring methylenes)].

1. temperaturewas cooled to ca. 5°
2. temperaturewhilst maintaining the temperature below 20°
3. extraction, and was then extracted with chloroform
4. customn-propanol, 3:1 (7×100 ml.) and the combined extracts evaporated down
5. customto give a white solid which
6. dry with materialwas dried in vacuo over fresh phosphorus pentoxide
7. customFreeze-drying of the aqueous layer and similar work-up to the above gave further product (total yield 26.0 g., 65%)
8. customA sample of the solid was recrystallised from chloroform