Sequential One-Pot Synthesis of 2-Aminothiazoles Using Corresponding Ketones: Insights into Their Structural Features

Abstract

2-Aminothiazoles have been synthesized by a one-pot, two-step sequential procedure in solution state which does not involve the isolation of intermediates. It involves α-halogenation of corresponding precursor ketones followed by condensation with substituted thiourea derivatives. All the products were analyzed by IR, NMR, mass spectral techniques and four of them were evaluated crystallographically. One of them crystallizes in the triclinic crystal system with space group P$\overline{1}$, while, all the other compounds crystallize in the monoclinic crystal system in two different space groups viz. P2₁/c and P2₁/n. The modified 2-aminothiazole core did not show any change in the intermolecular interaction. The N-H…N interaction predominates over other interactions forming centrosymmetric head to head dimer with the neighboring atoms. This feature is observed in all the molecules except N-(4-(4-bromophenyl)-3-(2,5-dimethylphenyl)thiazol-2(3H)-ylidene)-2,5-dimethylaniline.

Keywords:

• One-pot two-step reaction
• 2-aminothiazoles
• structural modification
• crystal structure
• weak interactions

Acknowledgement

H. N. is thankful to the Science and Engineering Research Board, New Delhi, for funding under young scientist scheme with the project no: SB/FT/CS-152/2014. N. L. P and N. S. B are thankful to University Grants Commission (UGC), New Delhi.