Ramatroban

Ramatroban
Clinical data
Trade namesBaynas
AHFS/Drugs.comInternational Drug Names
Routes of
administration
Oral (tablets)
ATC code
  • None
Legal status
Legal status
  • Rx-only (JP)
Identifiers
IUPAC name
  • 3-((3R)-3-{[(4-fluorophenyl)sulfonyl]amino}-1,2,3,4-tetrahydro-9H-carbazol-9-yl)propanoic acid
CAS Number
PubChem CID
IUPHAR/BPS
ChemSpider
UNII
KEGG
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.159.668
Chemical and physical data
FormulaC21H21FN2O4S
Molar mass416.47 g·mol−1
3D model (JSmol)
SMILES
  • C1CC2=C(CC1NS(=O)(=O)C3=CC=C(C=C3)F)C4=CC=CC=C4N2CCC(=O)O
InChI
  • InChI=1S/C21H21FN2O4S/c22-14-5-8-16(9-6-14)29(27,28)23-15-7-10-20-18(13-15)17-3-1-2-4-19(17)24(20)12-11-21(25)26/h1-6,8-9,15,23H,7,10-13H2,(H,25,26)/t15-/m1/s1
  • Key:LDXDSHIEDAPSSA-OAHLLOKOSA-N

Ramatroban (INN; also known as BAY u3405)[1] is a thromboxane receptor antagonist.[2] It is also a DP2 receptor antagonist.[3]

Ramatroban is indicated for the treatment of coronary artery disease.[4] It has also been used for the treatment of asthma.[5]

It has been suggested that ramatroban, by modulating DP2 receptor, can reverse viremia-associated proinflammatory and prothrombotic processes which are similar to those induced by SARS-Cov-2. Hence, ramatroban, that has been used for the treatment of allergic rhinitis in Japan for the past two decades with a well established safety profile, merits investigation as a novel immunotherapy for the treatment of COVID-19 disease, although no clinical trial has yet been conducted.[6]

Ramatroban was developed by the German pharmaceutical company Bayer AG and is co-marketed in Japan by Bayer Yakuhin then marketed by Kyorin Pharmaceutical and Nippon Shinyaku Co., Ltd. under the trade name Baynas.

It is a tetrahydrocarbazolamine derivative and cyclized tryptamine.

Synthesis

The synthesis has been described:[7][8][9] Cmp#4[10] Patent:[11]

The starting material is called 1,4-cyclohexanedione monoethylene glycol ketal aka 1,4-Dioxaspiro[4.5]decan-8-one [4746-97-8]. The Borsche–Drechsel cyclization between (1) and Phenylhydrazine gives 5-Oxo-tetrahydrocarbazole ethylene ketal [54621-12-4] (2). Hydrolysis of the ketal protecting group gives 1,2,4,9-tetrahydrocarbazol-3-one [51145-61-0] (3). Reduction of the ketone with sodium borohydride gives 2,3,4,9-tetrahydro-1H-carbazol-3-ol [14384-34-0] (4). Acetylation by treatment with vinyl acetate [108-05-4] gives (3R)-3beta-Acetoxy-1,2,3,4-tetrahydro-9H-carbazole, PC59051734 (5a) & (3S)-1,2,3,4-Tetrahydro-9H-carbazole-3-ol, PC8142712 (5b). These can be separated at this stage into pure (S) for the next step. A Mitsunobu reaction in the presence of DPPA leads to an Azide with pure Walden inversion kinetics w/o racemization. The Staudinger reduction of the azide in situ gives (R)-3-Amino-1,2,3,4-tetrahydrocarbazole [874-937-6] [116650-33-0] (6).

References

  1. "Ramatroban (compound)". PubChem. National Center for Biotechnology Information. Retrieved 22 June 2019.
  2. Sugimoto H, Shichijo M, Iino T, Manabe Y, Watanabe A, Shimazaki M, et al. (April 2003). "An orally bioavailable small molecule antagonist of CRTH2, ramatroban (BAY u3405), inhibits prostaglandin D2-induced eosinophil migration in vitro". The Journal of Pharmacology and Experimental Therapeutics. 305 (1): 347–352. doi:10.1124/jpet.102.046748. PMID 12649388. S2CID 10016709.
  3. Royer JF, Schratl P, Carrillo JJ, Jupp R, Barker J, Weyman-Jones C, et al. (September 2008). "A novel antagonist of prostaglandin D2 blocks the locomotion of eosinophils and basophils". European Journal of Clinical Investigation. 38 (9): 663–671. doi:10.1111/j.1365-2362.2008.01989.x. PMID 18837743.
  4. Fiedler VB, Seuter F, Perzborn E (December 1990). "Effects of the novel thromboxane antagonist Bay U 3405 on experimental coronary artery disease" (PDF). Stroke. 21 (12 Suppl): IV149 – IV151. PMID 2260140.
  5. Endo S, Akiyama K (November 1996). "[Thromboxane A2 receptor antagonist in asthma therapy]". Nihon Rinsho. Japanese Journal of Clinical Medicine (in Japanese). 54 (11): 3045–3048. PMID 8950952.
  6. Rizk JG, Kalantar-Zadeh K, Mehra MR, Lavie CJ, Rizk Y, Forthal DN (September 2020). "Pharmaco-Immunomodulatory Therapy in COVID-19". Drugs. 80 (13): 1267–1292. doi:10.1007/s40265-020-01367-z. PMC 7372203. PMID 32696108.
  7. "Synthesis of (R)-Ramatroban". Synfacts. 8 (08): 0822–0822. August 2012. doi:10.1055/s-0032-1316596.
  8. Busto E, Gotor-Fernández V, Gotor V (May 2012). "Asymmetric chemoenzymatic synthesis of ramatroban using lipases and oxidoreductases". The Journal of Organic Chemistry. 77 (10): 4842–8. doi:10.1021/jo300552v. PMID 22515546.
  9. Rosentreter U, Böshagen H, Seuter F, Perzborn E, Fiedler VB (December 1989). "Synthesis and absolute configuration of the new thromboxane antagonist (3R)-3-(4-fluorophenylsulfonamido)-1,2,3,4-tetrahydro-9-carbazolepropan oic acid and comparison with its enantiomer". Arzneimittel-Forschung. 39 (12): 1519–21. PMID 2624597.
  10. Gardner, P. D., Haynes, G. R., Brandon, R. L. (October 1957). "Formation of Dieckmann Reaction Products under Acyloin Conditions. Competition of the Two Reactions". The Journal of Organic Chemistry. 22 (10): 1206–1210. doi:10.1021/jo01361a021.
  11. Horst Bohagen, et al. U.S. patent 5,374,647 (1994 to Bayer AG).