| Identification | Back Directory | [Name]
1,3,4-Thiadiazole | [CAS]
289-06-5 | [Synonyms]
1,3,4-thiadiazole
Ceftezole Impurity 12
Ceftezole Impurity 15 | [Molecular Formula]
C2H2N2S | [MDL Number]
MFCD01311030 | [MOL File]
289-06-5.mol | [Molecular Weight]
86.12 |
| Chemical Properties | Back Directory | [Melting point ]
42.5°C | [Boiling point ]
204°C | [density ]
1.299 (estimate) | [refractive index ]
1.5300 (estimate) | [form ]
solid | [pka]
-0.33±0.10(Predicted) |
| Hazard Information | Back Directory | [Description]
1,3,4-Thiadiazole is a five-membered, aromatic, weakly basic, planer, electron-deficient, conjugated heterocyclic ring system comprised of two carbon atoms, one sulfur atom, and two pyridine-like nitrogen atoms present at the 3- and 4-positions of the ring. The dipole moment (3.25 D) for 1,3,4-thiadiazole suggests that it is a polar symmetric molecule with pseudo-aromatic character. The carbon atoms at the 2- and 5-positions are electron deficient because of the inductive effect of nitrogen and sulfur and thus they are inert toward electrophilic substitution but reactive toward nucleophilic attack. | [Uses]
1,3,4-Thiadiazole, a bioisostere of the thiazole ring, has been used in the synthesis of cephalosporine and cefazedone, which are used as antibiotics. Megazole is another 1,3,4-thiadiazole-based drug, widely used in the treatment of African trypanosomes, also known as sleeping sickness. Azetepa, a phosphoruscontaining drug, has been used for the treatment of cancer. Tebtheuron is known as a broad-spectrum herbicide and is used to control a variety of weeds and herbaceous and woody plants. Numerous thiadiazole derivatives are patented as bactericides, insecticides, and fungicides. | [Definition]
ChEBI: 1,3,4-thiadiazole is a thiadiazole. | [Chemical Reactivity]
Atomic charges have been calculated by the DFT method. The maximum charge was found at the S atom (0.818) and thus it is the favorite position for soft nucleophilic attack. The atomic charge on each carbon is ?0.3275. Because of the presence of the two pyridine-like nitrogen atoms in the ring, which make the C2 - and C5 -positions electronically poor, nucleophilic substitution of the leaving groups present at either the C2 - or C5 -position becomes highly facile. However, the atomic charge on N3 and N4 (?0.0308) makes them preferential sites for electrophilic attack and readily N-alkylated or N-acylated. In strongly basic conditions the thiadiazole ring leads to ring fission. | [Biological Activity]
Anti-inflammatory,antivira and antimicrobial. |
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