Aniline → 4-Hydroxy-1,1-dioxo-N-phenyl-1,2-dihydro-1-benzothiopyran-3-carboxamide

Participants

Reaction Steps

Preparation by Aminolysis of the β-Ketoester. -- A mixture of 11.7 g. (0.05 mole) of methyl 4-hydroxy-2H-1-benzothiopyran-3-carboxylate 1,1-dioxide, 7.0 g. (0.075 mole) of aniline, and 250 ml. of xylene was refluxed for 16 hr. in a Soxhlet apparatus, the thimble of which contained 20 g. of Linde type 4A molecular sieve. The mixture was cooled and the resulting precipitate was collected to give 12.8 g. (81%) of product, m.p. 204°-208° dec. Recrystallization from ethyl acetate gave 11.4 g. material, m.p. 205°-208° dec.

Provenance & Evidence