Effect of substitution on molecular conformation and packing features in a series of aryl substituted ethyl-6-methyl-4-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates

Synthesis and Antitubercular Activity of 2‐(substituted phenyl/benzyl‐amino)‐6‐(4‐chlorophenyl)‐5‐(methoxycarbonyl)‐4‐methyl‐3,6‐dihydropyrimidin‐1‐ium Chlorides

“…The 3,6‐dihydropyrimidine analogues 7–13 and 15 were synthesized as outlined in Scheme 1 starting from methyl 4‐(4‐chlorophenyl)‐6‐methyl‐2‐oxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylate 4 which has been synthesized by Biginelli reaction by employing Lewis acid according to the procedure described in our previous study (26). The purification of the product was accomplished using Et‐OH by recrystallization method and the yield of the product was 66%.…”

Insights into conformational and packing features in a series of aryl substituted ethyl-6-methyl-4-phenyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates

“…1 It is noteworthy that PIYYEC is also isostructural with PYR 1(para-F), 3 (meta-Cl), 4 (para-methyl), 5 (para-N,N-dimethyl) compounds (in the thioxo series). ILAHEI (ortho chloro in oxo series) is isostructural with PYR1 (para F) in oxo series.…”

“…The tetrahydropyrimidine and the aryl ring are nearly orthogonal to each other, the dihedral twist being 86.4 (2) . The carbon atom C7 is disordered over two sites, the major occupancy refining to a value of 0.57(1) and the minor being 0.43 (1). The crystal packing is built up from interplay of hydrogen bonds involving strong donors and acceptors, namely H1N and H2N, forming N-H/O]C hydrogen bonds, generating a 2D-sheet like structure, forming a R 4 4 (20) ring motif [ Fig.…”

“…1 These compounds contain multiple functional groups and exhibit significant conformational flexibility with respect to the aryl ring and the ester moiety. Both these functional groups can rotate independently with respect to the dihydropyrimidine (DHPM's) ring.…”

The CH/π Hydrogen Bond: Implication in Crystal Engineering

“…Chopra and coworkers studied the crystal structures of a series of compounds related to structure 18, that is, with X = F, Cl, Me, OMe, NMe 2 , and Y = O [74] and S [75]. These Guru Row and coworkersstudied the crystal structures of a series of fluorinated compounds; Figure 1.13 shows that CH/π , CH/F and CH/O hydrogen bonds cooperatively work in stabilising the crystal conformation and network [76].…”