Table 1. Investigation of Bases for N-Benzylation of Isatoic Anhydride under Different Temperature Conditions for Scheme 1.
| entry | base | temp. (°C) | time (h) | conversion (%) |
|---|---|---|---|---|
| 1A1 | NaH | 0 | 24 | 30 |
| 1A2 | NaH | 30 | 12 | 48 |
| 1A3 | NaH | 80 | 06 | trace |
| 1A4 | NaOH | 0 | 24 | 16 |
| 1A5 | NaOH | 30 | 12 | 18 |
| 1A6 | NaOH | 80 | 06 | nil |
| 1A7 | K2CO3 | 0 | 24 | 17 |
| 1A8 | K2CO3 | 30 | 12 | 43 |
| 1A9 | K2CO3 | 80 | 06 | trace |
| 1A10 | Na2CO3 | 0 | 24 | 16 |
| 1A11 | Na2CO3 | 30 | 12 | 39 |
| 1A12 | Na2CO3 | 80 | 06 | trace |
| 1A13 | Cs2CO3 | 0 | 24 | 15 |
| 1A14 | Cs2CO3 | 30 | 12 | 47 |
| 1A15 | Cs2CO3 | 80 | 06 | trace |
| 1A16 | DIPA | 0 | 24 | nil |
| 1A17 | DIPA | 30 | 24 | 13 |
| 1A18 | DIPEA | 0 | 24 | nil |
| 1A19 | DIPEA | 30 | 24 | 13 |