NEW MATERIAL: A compound of formula I [X is S, O, NR' (R' is H or lower alkyl); R1, R2 and R3 each H or lower alkyl; R4 and R5 are each H or lower alkyl, but R4 and R5 are not simultaneously H; (n) is 0-5; A is pyridyl, thienyl, furil or the like; B is H, -COOH, -CH2OH, -CHO or the like].
EXAMPLE: Ethyl 6-[(2,2,4,4-tetramethyl-thiochroman-6-yl)-ethynyl] nicotinate.
USE: Medicines for the medical treatment of cutaneous disease such as acne, Darier's disease, psoriasis, eczema, atopic dermatitis, epithelial cancer or the like. Further effective for the arthritis and the other immunological disease.
PROCESS: A compound of formula II, and a compound of the formula, X'- A-(CH2)n-B (X' is halogen; B is H, protected acid, alcohol, ketone, or the like), are reacted in the presence of primary copper iodide and Pd(PQ3)2Cl2 (Q is phenyl), to obtain the compound of formula I.
