Synthesis of a clathrate host for formamides, N-[2-(3,5-dinitrobenzoylamino)-6-methylphenyl]phthalimide, and analysis of the interactions in the host–guest complex

A clathrate host, N-[2-(3,5-dinitrobenzoylamino)-6-methylphenyl]phthalimide 1 is designed to achieve inclusion of N-substituted formamides. N,N-Dialkylformamides HCONR2 of various sizes 2a–e [2a: R = Me; 2b: R = Et; 2c: R = Pri; 2d: R2 = –(CH2)5–, 2e: R2 = –(CH2)2O(CH2)2–] and dimethyl sulfoxide have been included as the guests in a clathrate host 1, in the ratio 1∶1 in each case. The interaction between the host and guest has been investigated by X-ray analysis of complex 1·2c (1∶1). The phthalimide plane and the N-phenyl group are orthogonal, which makes a suitable space for recognition of the formamides.