Crystal structure of 2-acetyl-5-(3-methoxyphenyl)-3,7-dimethyl-5H-1,3-thiazolo[3,2-a]pyrimidine-6-carboxylate

In the title mol­ecule, C₂₀H₂₂N₂O₄S, the pyrimidine ring is in a flattened half-chair conformation and the 3-meth­oxyphenyl substituent is in an axial arrangement. The thia­zole ring forms a dihedral angle of 81.3 (1)° with the benzene ring. In the crystal, weak C—H...S inter­actions link mol­ecules into chains along [001]. In addition, there are π–π inter­actions between inversion-related thia­zole rings with a centroid–centroid distance of 3.529 (2) Å. The ethyl group was refined as disordered over two sets of sites with an occupancy ratio of 0.52 (3):0.48 (2).

Crystal structure of 1-(2,4-di­methyl­phen­yl)-2-(4-tri­methyl­silyl-1H-1,2,3-triazol-1-yl)ethanone

The asymmetric unit of the title compound, C₁₅H₂₁N₃OSi, contains two mol­ecules with similar conformations (r.m.s. overlay fit for the 20 non-H atoms = 0.163 Å). The dihedral angles between the planes of the 1,2,3-triazole and 2,4-di­methyl­benzene rings are 27.0 (3) and 19.5 (3)°. In the crystal, mol­ecules are linked by very weak C—H...O and C—H...N hydrogen bonds to generate [100] chains. The chains are cross-linked by C—H...π inter­actions.