Cyclic and acyclic products from the reactions between methyl 3-oxobutanoate and arylhydrazines
James L Wardell1, Janet M S Skakle, John N Low
1Instituto de Química, Departamento de Química Inorgânica, Universidade Federal do Rio de Janeiro, 21945-970 Rio de Janeiro, RJ, Brazil.
Abstract:
The molecules of methyl 3-(2-nitrophenylhydrazono)butanoate, C(11)H(13)N(3)O(4), (I), and methyl 3-(2,4-dinitrophenylhydrazono)butanoate, C(11)H(12)N(4)O(6), (II), both prepared from methyl 3-oxobutanoate and the corresponding nitrophenylhydrazine, exhibit polarized molecular electronic structures; in each of (I) and (II), the molecules are linked into chains by a single C-H...O hydrogen bond. The molecules of 5-hydroxy-3-methyl-1-phenyl-1H-pyrazole, C(10)H(10)N(2)O, (III), prepared by the reaction of methyl 3-oxobutanoate and phenylhydrazine, are linked into chains by a single O-H...N hydrogen bond. The reaction between methyl 3-oxobutanoate and 3-nitrophenylhydrazine yields 5-hydroxy-3-methyl-1-(3-nitrophenyl)-1H-pyrazole, (IV), which when crystallized from acetone yields 4-isopropylidene-3-methyl-1-(3-nitrophenyl)-1H-pyrazol-5(4H)-one, C(13)H(13)N(3)O(3), (V).
Related Concept Videos
03:08Hydroboration-Oxidation of Alkenes
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
01:28Multiple Halogenation of Methyl Ketones: Haloform Reaction
02:34Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
03:00Preparation of Epoxides
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy acids to...
02:15Preparation of Alcohols via Addition Reactions
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...