Table 1.
Entry | Solvent | Additive | Time | T (°C) | Discoloration |
---|---|---|---|---|---|
1 | H2O | none | 2 h | 70 | No |
2 | THF | none | 2 h | reflux | No |
3 | H2O | TFA 10 mol % | 1 h | 70 | No |
4 | THF | TFA 10 mol % | 20 min | reflux | Yes |
5 | H2O/THF | TFA 10 mol % | 20 min | 70 | Yes |
Entry | Solvent | Additive | Time | T (°C) | Discoloration |
---|---|---|---|---|---|
1 | H2O | none | 2 h | 70 | No |
2 | THF | none | 2 h | reflux | No |
3 | H2O | TFA 10 mol % | 1 h | 70 | No |
4 | THF | TFA 10 mol % | 20 min | reflux | Yes |
5 | H2O/THF | TFA 10 mol % | 20 min | 70 | Yes |