2-Aminobenzothiazole

2-Aminobenzothiazole

Names
Other names 2-aminobenzthiazole
Identifiers
CAS Number	136-95-8
3D model (JSmol)	Interactive image
ChEBI	CHEBI:167751
ChEMBL	ChEMBL329785
ChemSpider	8382
ECHA InfoCard	100.004.790
EC Number	205-268-4
PubChem CID	8706
UNII	08K5TLY3EQ
UN number	2811 (2-AMINOBENZOTHIAZOLE)
CompTox Dashboard (EPA)	DTXSID1024467
InChI InChI=1S/C7H6N2S/c8-7-9-5-3-1-2-4-6(5)10-7/h1-4H,(H2,8,9) Key: UHGULLIUJBCTEF-UHFFFAOYSA-N
SMILES C1=CC=C2C(=C1)N=C(S2)N
Properties
Chemical formula	C7H6N2S
Molar mass	150.20 g·mol−1
Density	1.753 g/cm3 [1]
Melting point	126–129 °C (259–264 °F; 399–402 K)
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H319, H400
Precautionary statements	P264, P264+P265, P270, P273, P280, P301+P317, P305+P351+P338, P330, P337+P317, P391, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

2-Aminobenzothiazole is the organic compound with the formula C₆H₄S(N)CNH₂. It is related to the parent benzothiazole, but with an amino group at the unique methyne position on the thiazole ring. As confirmed by X-ray crystallography, it is a planar molecule, which exists as the amine tautomer. ^[1]

2-Aminobenzothiazoles are often prepared by cyclization of 2-bromo-substituted arylthioureas. ^[2]

BrC₆H₄NHC(S)NH₂ → C₆H₄SNCNH₂ + HBr

Isothiocyanic acid, which can be generated in situ from sodium thiocyanate, adds to anilines to also afford 2-aminobenzothiazoles. ^[3] Many other methods are available. ^[4]

Diazotization of 2-aminobenzothiazoles gives diazonium salts. These salts undergo azo coupling with anilines. In this way some are prepared some useful dyes such as Basic Blue 54. ^[5]

References

1. Altaf, Muhammad; Stoeckli-Evans, Helen (2009). "1,3-Benzothiazol-2-amine". Acta Crystallographica Section E: Structure Reports Online. 65 (8): o1894. Bibcode:2009AcCrE..65o1894A. doi:10.1107/S1600536809027561. PMC   2977242 . PMID   21583584.
2. Ding, Qiuping; He, Xiaodan; Wu, Jie (2009). "Synthesis of 2-Aminobenzothiazole via Copper(I)-Catalyzed Tandem Reaction of 2-Iodobenzenamine with Isothiocyanate". Journal of Combinatorial Chemistry. 11 (4): 587–591. doi:10.1021/cc900027c. PMID   19449803.
3. Allen, C. F. H.; VanAllan, J. (1942). "2-Amino-6-Methylbenzothiazole". Organic Syntheses . 22: 16. doi:10.15227/orgsyn.022.0016 .
4. Prajapati, Neelam P.; Vekariya, Rajesh H.; Borad, Mayuri A.; Patel, Hitesh D. (2014). "Recent Advances in the Synthesis of 2-Substituted Benzothiazoles: A Review". RSC Adv. 4 (104): 60176–60208. Bibcode:2014RSCAd...460176P. doi:10.1039/C4RA07437H.
5. Berneth, Horst (2008). "Methine Dyes and Pigments". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a16_487.pub2. ISBN   978-3-527-30385-4.