Table 2.
Synthesis of 10,10-dioxo-3-carboxamides-thioxanthen-9-ones.a

| R | Product | Yieldb | R | Product | Yieldb |
|---|---|---|---|---|---|
|
|
9a | 36% |
|
9g | 29% |
|
9b | 46% |
|
9h | 67% |
|
|
9c | 24% |
|
9i | 57% |
|
9d | 30% |
|
9j | 56% |
|
9e | 31% |
|
9k | 71% |
|
|
9f | 66% |
Reactions were run using carboxylic acid-sulfone 8, 1.1 equiv. of amine, 1.1 equiv. of HBTU or BOP and 5.0 equiv. of DIPEA (Diisopropylethyl amine) in 5.0 mL of solvent (CH2Cl2) at RT.
Isolated crude yields are reported.