
TY  - JOUR
A1  - Guard, JAM 
A1  - Steel, PJ 
T1  - Heterocyclic Tautomerism. V. X-Ray Crystal Structures of Two 5-Substituted 1,2,4-Thiadiazol-3-ones
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1995
VL  - 48
IS  - 9
SP  - 1609
EP  - 1615
KW  - 
UR  - https://doi.org/10.1071/CH9951609 
N2  - Contrary to a recent report, 3-hydroxy-5-phenyl-1,2,4-thiadiazole is shown to exist as the OH tautomer (2a). At 130 K crystals of (2a) are monoclinic, P21/n, a 5.453(3), b 4.956(2), c 27.28(2) &#506;, &#946; 94.12(5)&#176;, Z = 4; the structure was refined to a conventional R[I > 2&#963;(I)] 0.051. 5-Benzoylamino-1,2,4-thiadiazol-3-one is shown to exist as the N(2)H tautomer (3b) but with a contribution to the structure from a bicyclic or zwitterioni resonance contributor containing an S-O bond. At 130 K crystals of (3b) are monoclinic, Pn , a 3.771(1), b 15.465(4), c 8.105(1) &#506;, &#946; 98.72(2)&#176;, Z = 2; the structure was refined to a conventional R[I > 2&#963;(I)] 0.038. 
ER  -

