The invention relates to compounds of the Formula (I), Formula (I) wherein R1 and R2 are as described in the description, their preparation and their use as pharmaceutically active compounds. Said compounds particularly act as immunomodulating agents.本發明係關於式(I)化合物,式(I)其中R1及R2如說明書中所述,其製備及其作為醫藥學上活性化合物之用途。該等化合物尤其用作免疫調節劑。