Nationality Bulgarian Name Khristo Ivanov | Role Organic Chemist Residence Sofia, Bulgaria | |
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Fields Organic Chemistry, Organic Synthesis Institutions University of Sofia,
Faculty of Chemistry and Pharmacy Died February 16, 2004, Sofia, Bulgaria | ||
Khristo Ivanov (Bulgarian: Христо Иванов) (May 3, 1916 – February 16, 2004) was a Bulgarian organic chemist.
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Life and career
Khristo Ivanov (Bulgarian: Христо Иванов) was born in the town of Dobrich, Bulgaria, on May 3, 1916. His father Ivan Christov was hardware man and cartwright, who died after World War I, in 1918 when Christo Ivanov was two. His mother, Elena Christova, took care of her one and only son. Khristo Ivanov obtained his degree in chemistry from the Physical-Mathematical Faculty of Sofia University in 1939. After teaching Chemistry at school level in the towns of Popovo and Karlovo for a couple of years, he received the position of regular Assistant Professor at the same faculty in 1946. He had specialized in the field of Organic Synthesis at the universities of Leipzig (1953–1954) and Moscow (1956–1957). His scientific career is associated with the University of Sofia – its Physical-Mathematical Faculty and the later Faculty of Chemistry that branched off from it (1961). He received an Associate Professorship in 1957 and full Professorship and the Chair of Organic Chemistry in 1963. Ivanov was Head of the Department of Organic Chemistry from 1963 until his retirement in 1984, as well as being Vice Rector of Sofia University (1962–1968), Dean of the Faculty of Chemistry (1972–1976), and member of the Presidium (1980–1986) and President of the Commission of Chemical Sciences at the Higher Attestation Commission. For his research and academic input, he was awarded the Cyril-and-Methodius medal (1st degree), the People's-Republic-of-Bulgaria medal (1st degree), and the Plaque with Necklace of the "St. Kliment Ohridski" University of Sofia.
Ivanov died on February 16, 2004 at the age of 87 after a short illness. On the occasion of his 100th anniversary a comprehensive biographical article has been recently published.
Scientific works
Khristo Ivanov continued the research started by his predecessor Dimitar Ivanov of the Bulgarian Academy of Sciences, publishing over 125 scientific papers and raising the Bulgarian school of Organic Chemistry to an international level. His main interests focused on the reactivity of CH-acidic compounds in an attempt to solve fundamental problems in the chemistry of carbanions and organometallic compounds. The results obtained enabled the elaboration of various synthetic methods for preparation of new organic compounds.
In collaboration with Peter Markov, Ivanov established for the first time the possibility for metalation of CH-acidic compounds with magnesium in liquid ammonia. He attempted to clarify the structure of the prepared organomagnesium compounds and explained the obtained results with the phenomenon of metalotropy. In acknowledgement of these scientific achievements the team was given in 1979 the Prof. Asen Zlatarov Award by the Bulgarian Academy of Sciences.
The Laboratory of Organic Synthesis supervised by Ivanov also made breakthroughs in organic synthesis. New synthetic methods were developed, involving the reaction of ambident nucleophilic reagents (prepared by metalation of esters, nitriles and amides of alkanoic and arylacetic acids) with N-acylated aldimines and ketimines. The resulting new derivatives of 3-acylaminopropanoic acids were transformed into various heterocyclic compounds: beta-lactams, 1,3-oxazines, 2-imidazolidinones, etc.
Ivanov and his lab studied reaction of 2-benzylbenzazoles with aromatic aldehydes in detail under phase-transfer catalysis or in aprotic solvents in the presence of a water solution of sodium hydroxide leading to 2-styrylbenzazols or alcohols having a benzazole ring. Detailed studies have been done under the conditions of the Michael reaction on the addition of metallic derivatives of CH-acidic compounds to substrates containing carbonyl or azomethine group or to substrates with an activated double bond.
Ivanov was the initiator of studies on the reaction of nucleophilic reagents with coumarins. A new interesting rearrangement of 3-substituted coumarins to 2-oxochromans-4-acetic acid derivatives was found for the first time. It is used for elaboration of preparative methods for conversion of nitriles, esters and amides of coumarin-3-carboxylic acid into the corresponding rearranged products.