Table 3.
Base-catalyzed hydrolysis rates (−kobs in M−1s−1) of amides 2x–5x (x = a–e) in two solvent systems.a Average values are shown where possible (see footnotes). Relative reaction rates (referenced to 4) are shown in parentheses.
| 1,4-Dioxane-D2O (1:1), NaOD, 70 °C a | Methanol-D2O (1:1), NaOD, 70 °C b | |||||||
|---|---|---|---|---|---|---|---|---|
| x= | 2x | 3x | 4x | 5x | 2x | 3x | 4x | 5x |
| a (H) | 2.1 × 10−5 (5.8) | 7.8 × 10−6 (2.2) | 3.6 × 10−6 (1) | 6.5 × 10−7 (0.2) | 1.1 × 10−4 | 2.9 × 10−5 | ND | ND |
| b (Cl) | 2.3 × 10−4 (82.1) | 1.8 × 10−5 (6.4) | 2.8 × 10−6 (1) | 1.2 × 10−6 (0.4) | 9.7 × 10−4 (88.2) | 7.0 × 10−5 (6.4) | 1.1 × 10−5(1) | 3.0 × 10−6 (0.3) |
| c (NO2) | 9.9 × 10−4 (33.0) | 1.0 × 10−4 (3.3) | 3.0 × 10−5 (1) | 3.7 × 10−5 (1.2) | 6.5 × 10−3 (92.9) | 4.2 × 10−4 (6.0) | 7.0 × 10−5(1) | 4.3 × 10−5 (0.6) |
| d (Me) | ND | 4.1 × 10−6 | NA | NE | ND | 1.7 × 10−5 (4.2) | 4.1 × 10−6(1) | NE |
| e (MeO) | ND | 4.8 × 10−6 | NE | NE | ND | 1.9 × 10−5 | NE | NE |
a Error estimation: ±13.8% (in the 1,4-dioxane system). (b) Error estimation: ±17.4% (in the methanol system). ND = not determined; NA = not available (due to the solubility problem); NE = not executable (due to very slow reaction).