The present invention relates to a compound of formula (I)or a salt thereof, wherein the substituents are as defined in the description, to compositions and use of the compounds in the treatment of diseases ameloriated by inhibition of phosphatidylinositol 3-kinase.本發明係關於一種式(I)化合物:或其鹽,其中取代基如本說明書中所定義,該等化合物之組合物,及該等化合物於治療藉由抑制磷脂醯肌醇3-激酶而改善之疾病的用途。