| Entry | R1 | R2 | R3 | Time/h | Yield/% | |
|
|
|
|
|
| 2 | 4 |
| 1 | A | H | Ph | 1 | 77 |
|
| 2 | A | H | Ph(CH2)2 | 2.5 | 0 | 14 |
| 3 | A | Boca | Ph(CH2)2 | 0.5 | 97 |
|
| 4 | B | H | Ph(CH2)2 | 0.5 |
| NIb |
| 5 | B | Boc | Ph(CH2)2 | 0.5 | 79 |
|
| 6 | C | H | Ph(CH2)2 | 0.5 |
| NI |
| 7 | C | Boc | Ph(CH2)2 | 0.5 | 94 |
|
| 8 | D | H | Ph | 0.5 | 35 |
|
| 9 | D | Boc | Ph | 1 | 87 |
|