Hekmat Bechir Antaki (H. Antaki)

H. B. F. Antaki, Cairo, circa 1960s

Contributions to the History of Chemistry

Hekmat Bechir Fathallah Antaki was an Egyptian organic chemist. He completed his doctoral degree at Queen Mary College, University of London, in 1950, under the supervision of J.R. Partington. He was elected a Fellow of the Chemical Society on 14 October 1948 (J. Chem. Soc., 1948, p. 104; DOI 10.1039/JR94800BA001). He returned to Egypt and joined the Research Institute for Tropical Medicine, Cairo, where he conducted an independent programme of research in heterocyclic chemistry between 1951 and 1967. He subsequently served as Director of the Research Institute of Medical Entomology, Cairo.

He published eight papers in four leading chemistry journals between 1951 and 1967. Working without university affiliation, he developed multicomponent condensation methods for the synthesis of pharmacologically relevant heterocyclic scaffolds. His 1962 paper was submitted from his home address in Agouza, Cairo — self-funded research by a working scientist.

The documents reproduced below are from his 1950 doctoral thesis, Queen Mary College, University of London.

The Two Privileged Scaffolds

Across eight papers, Antaki's work established two heterocyclic scaffolds, each now recognised in medicinal chemistry.

What the Field Said

Independent parties — patent attorneys, review authors, and research chemists — described his work in their own words. None was obliged to mention him.

"The synthesis of a 1H-pyrimido[1,2-a]quinoline appears to have first been reported by Antaki et al., J. Chem. Soc., pp. 551–555 (1951)."
— Pfizer, US 4,066,766 (1978)

"hexahydroquinoline derivatives… aroused our interest."
— Bossert and Vater, inventors of nifedipine, citing Antaki's 1963 paper at that step. Medicinal Research Reviews 9, 291 (1989).

Products of 4-methylpyridine and ethoxymethylene cyanoacetate "were first described by Antaki."
— Hermecz and Mészáros, the canonical review of the ring system. Advances in Heterocyclic Chemistry, Vol. 33 (1983).

Their products were "identical in m.p., ir, uv, and pmr spectra… as described by Antaki and Petrow" — confirmed by X-ray crystallography and NMR.
— Yale, Toeplitz, Gougoutas and Puar, Squibb Institute for Medical Research. J. Heterocyclic Chem. (1972/73).

The angular formulation "was revised by Antaki and Petrow to the linear structure, based upon the known reactivity of C₂-methylene in the 5α-series."
— Y. Ban and Y. Sato, Chem. Pharm. Bull. 1965, 13, 1073. (Ban and Sato then confirmed the linear structure independently by ozonolytic degradation.)

"Suitable reaction conditions are also reported by Antaki in J. Chem. Soc., 4877 (1963)."
— Zeneca, EP 0539154 (1997).

The full record — patents, reviews, reference works, and laboratory use, in their authors' own words: In Their Own Words

Recognition and Record

• Named reaction. His 1963 hexahydroquinoline synthesis has been formally classified as the Antaki synthesis, alongside the Hantzsch and Stankevich reactions, as one of three foundational multicomponent methods for that scaffold class. Oduselu et al., Frontiers in Chemistry, 2026. DOI: 10.3389/fchem.2026.1769586

  "Traditional multicomponent reactions such as the Hantzsch, Antaki, and Stankevich methods are discussed alongside more recent green synthetic strategies." — Oduselu et al., Frontiers in Chemistry, 2026.

• Pharmaceutical patents. Twenty-six confirmed citations in pharmaceutical patent filings, verified at text level.

  #	Patent	Assignee	Published	Paper cited
  1	US 3,538,086	CIBA (Switzerland)	1970-11-03	1951 JCS
  2	US 4,014,881	Pfizer	1977-03-29	1951 JCS + 1958 JACS
  3	US 4,017,625	Pfizer	1977-04-12	1951 JCS + 1958 JACS
  4	US 4,022,897	E.R. Squibb	1977-05-10	1951 JCS
  5	US 4,031,217	Pfizer	1977-06-21	1951 JCS + 1958 JACS
  6	US 4,041,163	Pfizer	1977-08-09	1951 JCS
  7	US 4,066,766	Pfizer	1978-01-03	1951 JCS + 1958 JACS
  8	US 4,122,274	Bristol-Myers	1978-10-24	1958 JACS
  9	US 4,209,620	Bristol-Myers	1980-06-24	1958 JACS
  10	US 4,223,031	Mead Johnson	1980-09-16	1951 JCS
  11	US 4,491,587	Mead Johnson	1985-01-01	1951 JCS
  12	US 4,762,840	Roussel-Uclaf (Sanofi)	1988	1951 JCS
  13	US 5,166,206	Merck	1992-11-24	1951 JCS
  14	EP 0539153	Zeneca	1993	1963 JCS
  15	EP 0539154	Zeneca	1993	1963 JCS
  16	US 5,258,390	ICI/AstraZeneca	1993-11-02	1963 JCS
  17	CA 2080950	ICI / Zeneca	1993	1963 JCS
  18	CA 2080949	ICI / Zeneca	1993	1963 JCS
  19	US 5,324,729	Merck	1994-06-28	1951 JCS
  20	US 5,340,819	ICI	1994-08-23	1963 JCS
  21	US 5,455,253	Zeneca	1995-10-03	1963 JCS
  22	US 5,484,792	ICI	1996	1963 JCS
  23	US 5,622,964	Zeneca	1997-04-22	1963 JCS
  24	US 8,716,319	Gilead Sciences	2014-05-06	1963 JCS
  25	WO 2015/002150	Shin Nippon Biomedical Labs	2015-01-08	1951 JCS
  26	US9745274	Shin Nippon Biomedical Labs	2017-08-29	1951 JCS

  The most recent granted patent — US9745274, Shin Nippon Biomedical Laboratories, Japan, granted 2017 — cites the 1951 paper as prior art and remains in force until 2034: eighty-three years after the paper's publication.

  Twenty-six patents verified at text level. Eleven independent companies. Six countries. 1970–2017. Full record with remarks: In Their Own Words

  Citation through the record: the examiner chain. Beyond the direct citations above, the United States Patent and Trademark Office's own prior-art search has, independently and more than once, traced its way back to Antaki by a second route — through a patent that itself cites him. In US patent practice an asterisk in the citation list marks a reference placed there by the examiner, not volunteered by the applicant. Antaki 1958 (JACS) carries that examiner asterisk on US 4,122,274 (Bristol-Myers, 1978). Two later, unrelated patent families on the same ring system in turn cite US 4,122,274:

  Patent	Assignee / subject	Connection to Antaki
  US 9,006,431	Pemirolast sodium, crystalline form (antiallergic)	Cites US 4,122,274 (examiner-cited); the product patent reproduces the Bristol-Myers synthesis by name in its own comparative examples
  US 9,586,955	Roche / PTC Therapeutics — compounds for spinal muscular atrophy (risdiplam)	Cites US 4,122,274 directly among its patent citations

  These two are not counted among the twenty-six direct citations above; they are included here as a documented second-order record of how far the citation trail extends.

• Encyclopedia of Reagents for Organic Synthesis. His 1958 paper is listed as Reference 1(a) in the entry for Ethyl Ethoxymethyleneacetoacetate in Wiley's Encyclopedia of Reagents for Organic Synthesis (e-EROS, 2001) — the most consulted synthetic chemistry reference in the discipline.
• Canonical reference works. Antaki's papers appear among the foundational references throughout the standard literature of heterocyclic chemistry.
  • The Chemistry of Heterocyclic Compounds (Weissberger series, Wiley) — cited across four volume-parts under three editors, 1961–1984: the 1951 paper in Klingsberg's Pyridine and Its Derivatives (Parts Two and Three, 1961–62); the 1963 and 1965 papers in Acheson's Vol. 9 (1973); the 1963 paper again in Thummel's "Carbocyclic Annelated Pyridines" (Part 5, 1984).
  • Comprehensive Heterocyclic Chemistry (Pergamon) — G. Jones cites the 1963 paper as the sole reference for the cyclohexane-1,3-dione variant of the Hantzsch synthesis (1st ed., 1984, DOI); the 2nd edition (1996) draws on the 1951, 1958 and 1962 papers across its treatment of structure, spectroscopy and synthesis.
  • Advances in Heterocyclic Chemistry (Academic Press) — cited by Kuthan (Vol. 34, 1983) and by Hermecz (Vol. 73, 1999); the foundational review by Hermecz and Mészáros (Vol. 33, 1983, DOI) calls the 1951 synthesis "unequivocal" and notes it was "first described by Antaki."
  • Houben-Weyl Methoden der Organischen Chemie — the 1951 paper cited in the German canonical synthetic encyclopedia (E 8a, 1993).
  • The Vitamin Co-Factors of Enzyme Systems — the 1951 ribosyl-benzimidazole paper cited in F. A. Robinson's monograph (Pergamon, 1966) in connection with vitamin B₁₂ methodology.
• Modern recognition and citation span. Bonacorso and Zanatta open their synthetic history of the pyrido[1,2-a]pyrimidinone ring system with the 1951 correction as their first reference (J. Heterocyclic Chem. 2006). E. I. Stankevich cited the 1963 paper directly in his own 1967 paper. The 1951 paper's confirmed citation span now reaches 75 years (1951–2026); the 1951 steroid paper remains in active use, cited by Momoli, Arcadi and colleagues as a practical alternative to Vilsmeier–Haack chloroformylation in 2025 (J. Org. Chem. 90, DOI: 10.1021/acs.joc.4c02981) — seventy-four years after publication.
• Queen Mary College London. His doctoral work (1950) and subsequent publications are documented in the alumni record of Queen Mary University of London. Queen Mary University of London — Alumni Remembered: Dr Hekmat Bechir Antaki (1923–1993)
• Pentacyclic fluorescent compounds (1967). First synthesis of an intensely blue-fluorescent pentacyclic benz[h]indenoquinoline — a class now studied for OLED materials, bioimaging, and DNA intercalation. Read more →

Scientific Contributions

• Full priority and relevance record: Contributions & Priority
• Named Reaction: The Antaki Synthesis (1963) — Hexahydroquinoline Chemistry

Structural Correction I: Resolving a Forty-Year Error in the Pyrido Series

In 1911, Palazzo and Tamburini prepared the first compound in the pyrido[1,2-a]pyrimidine series but assigned it the wrong structure (2-oxo instead of 4-oxo). This error was repeated by Seide (1925) and Crippa & Scevola (1937) and remained in the chemical literature for nearly forty years.

In 1951, Hekmat Bechir Fathallah Antaki, working with V. Petrow at Queen Mary College London, resolved the long-standing error. Using an independent synthesis (reacting 2-bromopyridine with ethyl β-aminocrotonate), they conclusively demonstrated that the correct structure was the 4-oxo isomer — borrowing the words of Hermecz and Mészáros (Advances in Heterocyclic Chemistry, Vol. 33, 1983): "unequivocal synthesis." This assignment was later confirmed by Adams and Pachter (1952) and explicitly credited as the definitive proof by Shur and Israelstam (1968) and by Hermecz and Mészáros, who further noted it was "first described by Antaki" (p. 269).

Structural Correction II: The Steroid Series

In Part II of his doctoral thesis (Queen Mary College, University of London, 1950, pp. 91–94), Antaki re-examined the indolo-cholestane that Dorée and Petrow had formulated as the angular isomer in 1935. The angular assignment had rested on surface-film measurements that were themselves inconclusive. Working from the established chemistry of the cholestanones, Antaki reassigned the structure from the angular [2′:3′-3:4] to the linear [2′:3′-3:2] cholestane. The revised assignment corrected a structure co-authored by V. Petrow, Antaki's collaborator and co-author on the published paper.

The full argument was set out in the thesis and published in compressed form in Part XII of the steroid work (J. Chem. Soc., 1951, 901). The reassignment was confirmed experimentally by Y. Ban and Y. Sato (Chem. Pharm. Bull., 1965, 13, 1073), who established the linear structure by ozonolytic degradation, carrying it through to the known Windaus–Uibrig acid. B. Robinson's review of the Fischer indole synthesis (Chem. Rev., 1969) records the same citation.

The correctly assigned fused indolo-steroid later served as the rigid molecular scaffold in a landmark experimental test of Förster energy-transfer theory as a spectroscopic ruler. Haugland, Yguerabide and Stryer (Proc. Natl. Acad. Sci. USA, 1969, 63, 23; DOI 10.1073/pnas.63.1.23) cited Antaki and Petrow (1951, 901) for the synthesis and Ban and Sato (1965) for the site of fusion of the indole to the steroid. The fixed geometry on which the method depends rests on that fusion assignment.

Vitamin B₁₂ and the Benzimidazole Glycosides

In his third 1951 paper (J. Chem. Soc., 1951, 2873–2877; DOI 10.1039/jr9510002873), Antaki and Petrow synthesised glycosylbenzimidazoles as potential inhibitors of vitamin B₁₂, preparing 2-methyl- and 2,5-dimethyl-1-(β-D-glucopyranosyl)benzimidazoles and the corresponding xylopyranosyl compounds by treatment of N-(tetra-O-acetyl-d-glucopyranosyl)-o-phenylenediamine with ethyl orthoacetate, isolation of the acetimidate intermediate, and acid-induced ring closure.

The paper entered two distinct lines of subsequent literature. In his authoritative review of B₁₂ chemistry (Bonnett, Chem. Rev., 1963, 63, 573; DOI 10.1021/cr60226a002), Antaki and Petrow were credited with having proposed at an early stage that the o-xylene substitution pattern shared by riboflavin and the 5,6-dimethylbenzimidazole nucleotide of B₁₂ derives from a common biogenetic source — a hypothesis Bonnett recorded in his biogenesis section. In their canonical review of benzimidazole nucleosides (Townsend and Revankar, Chem. Rev., 1970, 70, 395; DOI 10.1021/cr60265a005), the paper was cited for the specific synthetic procedure and the compounds prepared, situating the orthoacetate cyclisation as a distinct method within the developing benzimidazole-nucleoside methodology, separate from the Mamalis–Petrow–Sturgeon orthoformate route recorded in the same review.

Ultraviolet Spectroscopy: Establishing the Chromophore Record

In 1958, in his paper to the Journal of the American Chemical Society — submitted from the Research Institute for Tropical Medicine, Cairo, and received October 15, 1957 — Hekmat Bechir Fathallah Antaki published the first systematic ultraviolet absorption spectra of the pyrido[1,2-a]pyrimidine class (J. Am. Chem. Soc. 1958, 80, 3066–3069; DOI 10.1021/ja01545a041). He identified a constant feature across all compounds in the class — intense absorption in the region 330–390 mμ — and provided the mechanistic explanation: conjugative interaction with the β-amino-α,β-unsaturated ketone or nitrile chromophore. He further argued, in his own words:

"This may be considered as evidence for the major contribution of zwitterionic fully aromatic structures such as VIII to the resonance state of the molecule."

His 1962 paper (J. Org. Chem. 1962, 27, 1371–1374; DOI 10.1021/jo01051a058) further clarified the mechanistic origin of these bands. Both assignments were independently confirmed by Shur and Israelstam (1968) and were later adopted as the standard reference by Hermecz and Mészáros in their 1983 canonical review.

Medical Relevance

The scaffolds Antaki studied later became relevant across several areas of medicinal chemistry.

Cardiovascular. In their 1989 account of the path to nifedipine (Medicinal Research Reviews 9, 291), Bossert and Vater trace the chemistry from khellin through the chromones to the moment "hexahydroquinoline derivatives… aroused our interest" — citing Antaki's 1963 paper (ref. 7) at exactly that step. The hexahydroquinoline was the scaffold immediately preceding the 1,4-dihydropyridine that became nifedipine; Antaki appears again in the synthetic lineage (ref. 13), alongside Knoevenagel (1898). The broader 1,4-dihydropyridine calcium-channel-blocker class includes amlodipine, felodipine and nicardipine.

Antiparasitic. Antaki designed his programme for diseases of resource-limited settings; his 1962 paper noted schistosomicidal activity. The hexahydroquinoline scaffold has since drawn renewed interest in antimalarial drug discovery.

Anticancer / fluorescence. The pentacyclic benz[h]indenoquinoline he first made in 1967 belongs to a class now studied for DNA intercalation, topoisomerase inhibition, and blue-green fluorescence.

The Institution and the Eradication of Malaria in Egypt

In 1954 the Egyptian Ministry of Health constituted the Unit for Study and Eradication of Malaria in Egypt; Antaki joined that year, on returning from London. As malaria declined, the unit's mandate broadened, and in 1961 it became the Research Institute of Medical Entomology — described in its own materials as the only institute in the Arab world specialising in insect-borne diseases and a WHO training centre for vector-borne disease control. Antaki retired as director in 1983.

Egypt was certified malaria-free by the World Health Organization on 20 October 2024 — seventy years after the institution was founded, forty-one after he left it.

Publications

• Antaki, H.; Petrow, V. J. Chem. Soc. 1951, 901–904. DOI
• Antaki, H.; Petrow, V. J. Chem. Soc. 1951, 551–555. DOI
• Antaki, H.; Petrow, V. J. Chem. Soc. 1951, 2873–2877. DOI
• Antaki, H. J. Am. Chem. Soc. 1958, 80, 3066–3069. DOI
• Antaki, H. J. Org. Chem. 1962, 27, 1371–1374. DOI
• Antaki, H. J. Chem. Soc. 1963, 4877–4879. DOI
• Antaki, H. J. Chem. Soc. 1965, 2263–2264. PDF — Reproduced with the kind permission of the Royal Society of Chemistry.
• Antaki, H. J. Chem. Soc. C 1967, 1581–1582. DOI