Inhibitors of phosphatidylinositol 3-kinase

A compound of formula I

• in free or salt form, wherein
• R1 is —CO—NRxRy, where Rx and Ry together with the nitrogen to which they are attached form a substituted or unsubstituted 5- to 12-membered N-heterocyclic ring optionally including one or more ring hetero atoms selected from the group consisting of oxygen, nitrogen and sulphur;
• wherein the optional substituent is selected from hydroxy, —SO2—CH3 or aminocarbonyl;
• R2 is C1-C3-alkyl;
• Y is carbon;
• and
• R3 and R4 are each independently hydrogen, halo, hydroxy, cyano, amino, carboxy, C1-C8-alkylsulfanyl, C1-C8-alkylsulfinyl, C1-C8-alkylsulfonyl, —SO2NH2, C1-C8-alkyl, C1-C8-haloalkyl, amino-C1-C8-alkyl, amino-C1-C8-alkoxy, C1-C8-alkylaminocarbonyl, di(C1-C8-alkyl)aminocarbonyl, di(C1-C8-alkyl)amino-C1-C8-alkyl, di(C1-C8-alkyl)amino-C1-C8-alkoxy, C1-C8-acylamino, aminocarbonyl, C1-C8-alkoxycarbonyl, carboxy-C1-C8-alkyl, carboxy-C1-C8-alkoxy, a C3-C15-carbocycle, a 5- or 6-membered heterocyclic ring having one or more ring hetero atoms selected from the group consisting of oxygen, nitrogen and sulphur, C1-C8-alkylamino or di(C1-C8-alkyl)amino each being optionally substituted by amino, hydroxy, di(C1-C8-alkyl)amino or a 5- or 6-membered heterocyclic ring having one or more ring hetero atoms selected from the group consisting of oxygen, nitrogen and sulphur, or C1-C8-alkoxy optionally substituted by a 5- or 6-membered heterocyclic ring having one or more ring hetero atoms selected from the group consisting of oxygen, nitrogen and sulphur.