Benzothiazole, or more specifically 1,3-benzothiazole, is an aromatic heterocyclic compound with the chemical formula C
7H
5NS. It is colorless, slightly viscous liquid. Although the parent compound, benzothiazole is not widely used, many of its derivatives are found in commercial products or in nature. Firefly luciferin can be considered a derivative of benzothiazole.

The three structural isomers of benzothizaole are 1,3-benzothiazole, 1,2-benzothiazole and 2,1-benzothiazole.

Structure and preparation

Benzothiazoles consist of a 5-membered 1,3-thiazole ring fused to a benzene ring. The nine atoms of the bicycle and the attached substituents are coplanar.

Benzothiazoles are prepared by treatment of 2-mercaptoaniline with acid chlorides:[1]

C6H4(NH2)SH + RC(O)Cl → C6H4(NH)SCR + HCl + H2O

Uses

Benzothiazole occurs naturally in some foods but is also used as a food additive.[2] It has a sulfurous odor and meaty flavor.[3] The European Food Safety Authority assessment had "no safety concern at estimated levels of intake as a flavouring substance".[4]

The heterocyclic core of the molecule is readily substituted at the unique methyne centre in the thiazole ring. It is a thermally stable electron-withdrawing moiety with numerous applications in dyes such as thioflavin.[5] Accelerators for the sulfur vulcanization of rubber are based on 2-mercaptobenzothiazoles.[6] This ring is a potential component in nonlinear optics (NLO).[7] A benzothiazole derivative is suggested as a dye for arsenic detection.[8]

Pharmacology

Benzothiazole moiety is seen in certain dopamine-acting drugs, e.g. riluzole and pramipexole. Moreover, novel benzothiazole derivatives were shown to act as monoamine oxidase inhibitors or dopamine antagonists; these include:

See also

  • Benzothiazoles are related to thiazoles, which lack the fused benzene ring.
  • Benzoxazoles, which substitute an oxygen for the sulfur atom.

References

  1. ^ T. E. Gilchrist "Heterocyclic Chemistry" 3rd Edition, Longman, 1992.
  2. ^ Le Bozec, Lucille; Moody, Christopher J. (2009). "Naturally Occurring Nitrogen–Sulfur Compounds. The Benzothiazole Alkaloids". Australian Journal of Chemistry. 62 (7): 639. doi:10.1071/CH09126.
  3. ^ "Benzothiazole". The Good Scents Company. Retrieved 2020-10-06.
  4. ^ "Flavouring Group Evaluation 76, (FGE.76) - Consideration of sulphur-containing heterocyclic compounds evaluated by JECFA (59th meeting) structurally related to thiazoles, thiophene, thiazoline and thienyl derivatives from chemical group 29, miscellaneous". EFSA Journal. 6 (11): 875. 2008. doi:10.2903/j.efsa.2008.875.
  5. ^ Gill, Rupinder K.; Rawal, Ravindra K.; Bariwal, Jitender (2015). "Recent Advances in the Chemistry and Biology of Benzothiazoles". Archiv der Pharmazie. 348 (3): 155–178. doi:10.1002/ardp.201400340. PMID 25682746. S2CID 10421792.
  6. ^ Engels, Hans-Wilhelm; Weidenhaupt, Herrmann-Josef; Pieroth, Manfred; Hofmann, Werner; Menting, Karl-Hans; Mergenhagen, Thomas; Schmoll, Ralf; Uhrlandt, Stefan (2004), "Rubber, 4. Chemicals and Additives", Ullmann's Encyclopedia of Industrial Chemistry, doi:10.1002/14356007.a23_365.pub2, ISBN 3-527-30673-0
  7. ^ Hrobarik, P.; Sigmundova, I.; Zahradnik, P.; et al. (2010). "Molecular Engineering of Benzothiazolium Salts with Large Quadratic Hyperpolarizabilities: Can Auxiliary Electron-Withdrawing Groups Enhance Nonlinear Optical Responses?". Journal of Physical Chemistry C. 114 (50): 22289–22302. doi:10.1021/jp108623d.
  8. ^ Chauhan, Kalpana; Singh, Prem; Kumari, Bhawana; Singhal, Rakesh Kumar (2017-03-16). "Synthesis of new benzothiazole Schiff base as selective and sensitive colorimetric sensor for arsenic on-site detection at ppb level". Analytical Methods. 9 (11): 1779–1785. doi:10.1039/C6AY03302D. ISSN 1759-9679.
  9. ^ le Roux, Anandie; Petzer, Anél; Cloete, Stephanus J.; Petzer, Jacobus P. (2025-03-01). "An investigation of the monoamine oxidase inhibition properties of benzothiazole derivatives". Results in Chemistry. 14: 102142. doi:10.1016/j.rechem.2025.102142. ISSN 2211-7156.
  10. ^ Acar Çevik, Ulviye; Osmaniye, Derya; Sağlik, Begüm N.; Levent, Serkan; K. Çavuşoğlu, Betül; Karaduman, Abdullah B.; D. Özkay, Ümide; Özkay, Yusuf; Kaplancikli, Zafer A.; Turan, Gülhan (2020). "Synthesis of new benzothiazole derivatives bearing thiadiazole as monoamine oxidase inhibitors". Journal of Heterocyclic Chemistry. 57 (5): 2225–2233. doi:10.1002/jhet.3942. ISSN 1943-5193.
  11. ^ Turan, Gülhan; Osmaniye, Derya; Sağlik, Begüm Nurpelin; Çevik, Ulviye Acar; Levent, Serkan; Çavuşoğlu, Betül Kaya; Özkay, Ümide Demir; Özkay, Yusuf; Kaplancikli, Zafer Asım (2020-06-02). "Synthesis and monoamine oxidase A/B inhibitory evaluation of new benzothiazole-thiazolylhydrazine derivatives". Phosphorus, Sulfur, and Silicon and the Related Elements. 195 (6): 491–497. doi:10.1080/10426507.2020.1722667. ISSN 1042-6507.
  12. ^ Boateng, Comfort A.; Nilson, Ashley N.; Placide, Rebekah; Pham, Mimi L.; Jakobs, Franziska M.; Boldizsar, Noelia; McIntosh, Scot; Stallings, Leia S.; Korankyi, Ivana V.; Kelshikar, Shreya; Shah, Nisha; Panasis, Diandra; Muccilli, Abigail; Ladik, Maria; Maslonka, Brianna (2023-09-14). "Pharmacology and Therapeutic Potential of Benzothiazole Analogues for Cocaine Use Disorder". Journal of Medicinal Chemistry. 66 (17): 12141–12162. doi:10.1021/acs.jmedchem.3c00734. ISSN 0022-2623. PMC 10510399. PMID 37646374.
  13. ^ Sampson, Dinithia; Zhu, Xue Y.; Eyunni, Suresh V. K.; Etukala, Jagan R.; Ofori, Edward; Bricker, Barbara; Lamango, Nazarius S.; Setola, Vincent; Roth, Bryan L.; Ablordeppey, Seth Y. (2014-06-15). "Identification of a new selective dopamine D4 receptor ligand". Bioorganic & Medicinal Chemistry. 22 (12): 3105–3114. doi:10.1016/j.bmc.2014.04.026. ISSN 0968-0896. PMC 4096627. PMID 24800940.
Allikas: http://en.wikipedia.org/wiki/Benzothiazoles
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