2-(4-Biphenyl-1-yl)-1,3-diazaspiro[4,5]dec-1-en-4-thione

The title compound was prepared from imidazolinone 1 whose synthesis as well as 1H and 13C NMR spectra were published previously [1]. A solution of 1 (0.40 g, 1.3 mmol) in benzene (30 mL) was treated with a powder of phosphorus(V) sulfide (0.58 g, 2.6 mmol) and the resulting mixture was refluxed. After refluxing for 45 min the hot reaction mixture was filtered with charcoal (0.10 g). The filtrate was cooled and the crystaline solid obtained was collected by filtration and recrystallised from ethanol. The separated white crystals of compound 2 (0.16 g, 38 %) had the melting point of 228-230 °C.

The obtained thione 2 was tested for bacteriostatic activity against Mycobacterium tuberculosis H37Rv in the BACTEC 12B medium with the help of the radiometric system BACTEC 460 [2]. The inhibition activity of the said compound 2 was 22 %.

1H NMR (360 MHz, DMSO-d6):1.36-1.89 (m,10H), 7.49 (m, 1H-arom), 7.56 (t, 2H-arom), 7.82 (d, 2H-arom), 7.91 (d, 2H-arom), 8.21 (d, 2H-arom), 13.41 (s, 1H-NH).

13C NMR (90 MHz, DMSO-d6):22.2, 25.2, 36.9, 84.9, 126.8, 127.0, 127.2, 128.2, 128.5, 129.3, 139.1, 143.3, 157.9, 222.7.

Anal. Calc. For C20H20N2S: C 74.96, H 6.29, N 8.74, S 10.01. Found: C 75.17, H 6.36, N 8.64, S 10.18.