The Use of Rhodanine in Organic Synthesis and the Use of Aliphatic Diazo Compounds in Organic Synthesis

Dijksman, Derek J (1951) The Use of Rhodanine in Organic Synthesis and the Use of Aliphatic Diazo Compounds in Organic Synthesis. PhD thesis, University of Glasgow.

Abstract

The work described in Part I of this thesis resulted from some exploratory studies leading towards the synthesis of morphine. The condensation of rhodanine with aromatic o-carboxy-aldehydes and with an o-carboxy-ketone has been studied. a-Methyl opianate (I; R = R' = OMe, R" = Me) was condensed with rhodanine (II) to give 5-(2'-carbomethoxy-3':4'-dimethoxybenzylidene)-rhodanine (III; R = R' = OMe, R" = Me). Similarly a-methyl phthalaldehydate (I; R = R' = H, R" = Me) and phthalaldehydic acid (I; R = R' = R" = H) condensed with rhodanine to give o-carbomethoxy- (III; R = R' = H, R" = Me) and o-carboxybenzylidenerhodanine (III; R = R' = R" = H) respectively. o-Carboxyaceto-phenone (IV) on condensation with (II) gave o-carboxy-a-methy1rhodanine (V). o-Carboxybenzylidenerhodanines titrated as dibasic acids to phenolphthalein. It has been shown that the imino-group of the rhodanine ring is responsible for the second acidic function. Treatment of o-carboxybenzylidenerhodanines with sodium hydroxide gave 1:2-dihydro-l-keto-2-thianaphtha-lene-3-carboxylic acids (VI). Thus (III; R = R' = OMe, R" = Me) gave 1:2-dihydro-1-keto-7 :8-dimethoxy-thia-naphthalene -3-carboxylic acid (VI, R = R' = OMe, R" = H). Both o-carboxy and o-carbomethoxybenzylidenerhodanine on treatment with alkali gave (VI; R = R' = R" = H); similar treatment of (IV) gave 1:2-dihydro-1-keto-4-methyl-2-thianaphthalene-3-carboxylic acid (VI; R = R' = H, R" = Me). The thianaphthalene acids could be decarboxylated to give l:2-dihydro-1-keto-2-thianaphthalenes (VII). The sulphur atom in these thianaphthalenes was readily eliminated by ammonia and primary amines with the formation of 1:2-dihydro-1-ketoisoquinoline derivatives (VIII). Thus (VI; R = R' = R" = H) on heating with methyl amine gave 1:2 -dihydro -1 -keto-isoquinoline -3-carboxylic acid (VIII; R = R' = H, R" = Me). Treatment of 7:8-dimethoxy-, 4-methyl-, and unsubstitute d 1:2-dihydro-1-ke to-2-thianaphthalene-3-carboxylic acid with Raney nickel gave respectively 6:7-dimethoxyindan- 1-one (IX; R = R' = OMe, R" = H), 3-methylindan-1-one (IX; R = R' = H, R" = Me), and indan-l-one (IX; R = R' = R" = H). The latter compound was also obtained by the action of Raney nickel on 1:2-dihydro-1-keto-2-thianaphthalene. Treatment of 5-benzylidenerhodanine with Raney nickel gave (a) an unidentified product m. p. 189, (b) N-methyl-hydrocinnamamide, and (c) hydrocinnamamide. 5-Benzylidene-3-methylrhodanine on similar treatment gave a mixture of N-methyl-, and N-dimethylhydrocinnam-amide. The product obtained from the action of Raney nickel on 5-benzylidenerhodanine benzoate was not identified. An attempt to prepare substituted benzthiophenes by the alkaline hydrolysis of o-bromobenzylidenerhodanines was unsuccessful.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1951
• Depositing User: Enlighten Team
• Unique ID: glathesis:1951-78873
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 14:44
• Last Modified: 30 Jan 2020 14:44
• URI: https://theses.gla.ac.uk/id/eprint/78873