Compounds of formula I ** Formula ** in which R1 denotes A or Cyc, R2 denotes H, F, Cl, Br, OH, CN, NO2, A ', OA', SA ', SO2Me, COA' or CONA '2, R denotes Ar or Het, X1, X2, X3, X4 each, independently of each other, denotes CH or N, A denotes unbranched or branched alkyl with 1-10 C atoms, where two carbon atoms Adjacent can form a double bond and / or one or two non-adjacent CH- and / or CH2 groups can be replaced by N-, O- and / or S atoms and where 1-7 H atoms can be replaced by R4 , Cyc means cycloalkyl with 3-7 C atoms, which is unsubstituted or monosubstituted by OH, Hal or A, A 'denotes unbranched or branched alkyl with 1-6 C atoms, where 1-5 H atoms can to be replaced by F, R4 denotes F, Cl, Br, OH, CN, NO2, A ', OA', SA ', SO2Me, COA' or CONA'2, Ar denotes phenyl, which is unsubstituted, or mono-, di-, tri-, tetra- or pentas replaced by Hal, A, [C (R3) 2] pOR3, [C (R3) 2] pN (R3) 2, NO2, CN, [C (R3) 2] pCOOR3, N (R3) 2COA, NR 3SO2A, [C (R3) 2] pSO2N (R3) 2, S (O) nA, O [C (R3) 2] mN (R3) 2, NHCOOA, NHCON (R3) 2 and / or COA, R3 denotes H or unbranched or branched alkyl with 1-6 C atoms, Het denotes a saturated, unsaturated or aromatic mono- or bicyclic heterocycle having 1 to 4 atoms of N, O and / or S, which may be unsubstituted or mono- , di-, tri-, tetra- and pentas replaced by Hal, A, [C (R3) 2] nOR3, [C (R3) 2] nN (R3) 2, SR3, NO2, CN, COOR3, CON (R3) 2, NR3COA, NR3SO2A, SO2N (R3) 2, S (O) mA, O [C (R3) 2] nN (R3) 2, NHCOOA, NHCON (R3) 2, CHO, COA,>； = S,>； = NH,>； = NA and / or>； = O (carbonyl oxygen), Hal denotes F, Cl, Br or I, n1, n2, n3, n4 denote 1, m denotes 1, 2 or 3, n denotes 0, 1 or 2, p denotes 0, 1, 2, 3 or 4, provided that only one or two of X1, X2, X3, X4 denote N, and pharmaceutically acceptable salts, tautomers and stereoisomers thereof, including mixtures of the same in all proportions, excluding compounds ** Formula ** 2- [2 - [(2S) -2-ethoxycarbonylpyrrolidin-1-yl] -4,6-dimethyl-pyrimidin-5-carbonyl ] -1,3,3a, 4,6,6a-hexahyd
