Concept explainers
Interpretation:
The methylanilines, which can be formed by the reaction of
with sodium amide in ammonia, are to be determined.
Concept introduction:
Aryl halides, in the presence of a strong base, undergo substitution via elimination-addition mechanism.
In the first step, the base abstracts a proton attached to the ring carbon atom which is adjacent to the halogen. The proton and the halogen from adjacent carbon atoms are eliminated, and triple bond is created. This intermediate formed is benzyne.
The nucleophile then adds to any one of the triple bonded carbon atoms.
If the ring has a substituent other than halogen, the position of the nucleophile with respect to the substituent can be at two different sites, thus producing two different isomers.
In the overall reaction, the halogen is substituted by the nucleophile in product, and in the other product, the nucleophile gets attached to an adjacent carbon atom.
Want to see the full answer?
Check out a sample textbook solutionChapter 13 Solutions
Organic Chemistry - Standalone book
- A problem often encountered in the oxidation of primary alcohols to acids is that esters are sometimes produced as by-products. For example, oxidation of ethanol yields acetic acid and ethyl acetate: Propose a mechanism to account for the formation of ethyl acetate. Take into account the reversible reaction between aldehydes and alcohols:arrow_forwardWittig reactions with the following -chloroethers can be used for the synthesis of aldehydes and ketones. (a) Draw the structure of the triphenylphosphonium salt and Wittig reagent formed from each chloroether. (b) Draw the structural formula of the product formed by treating each Wittig reagent with cyclopentanone. Note that the functional group is an enol ether or, alternatively, a vinyl ether. (c) Draw the structural formula of the product formed on acid-catalyzed hydrolysis of each enol ether from part (b).arrow_forwardThe base-promoted rearrangement of an -haloketone to a carboxylic acid, known as the Favorskii rearrangement, is illustrated by the conversion of 2-chlorocyclohexanone to cyclopentanecarboxylic acid. It is proposed that NaOH first converts the a-haloketone to the substituted cyclopropanone shown in brackets and then to the sodium salt of cyclopentanecarboxylic acid. (a) Propose a mechanism for base-promoted conversion of 2-chlorocyclohexanone to the proposed intermediate. (b) Propose a mechanism for base-promoted conversion of the proposed intermediate to sodium cyclopentanecarboxylate.arrow_forward
- Identify the electrophile and the nucleophile in each of the following reaction steps and then draw curved arrows to illustrate the bond-making and bondbreaking processes.arrow_forwardStarting with benzene and using any other necessary reagents of your choice, what are the possible syntheses for the following compound?arrow_forwardGive the major organic product generated by the following reactionarrow_forward
- Give step-by-step mechanism for the following reactionarrow_forwardThe following substances can be prepared by a nucleophilic addition reaction between an aldehyde or ketoneand a nucleophile. Identify the reactants from which they were prepared. If the substance is an acetal, identifythe carbonyl compound and the alcohol; if it is an imine or enamine, identify the carbonyl compound and theamine. You do not have to consider stereochemistry. In cases where there is more than one answer, just giveone. Use Grignard reagents when an organometallic reagent is required. Draw the Grignard reagent as acovalent magnesium bromide.arrow_forwardAlkyl halides undergo nucleophilic substitution and elimination reactions. When the kinetics of the reaction are measured, if the rate of the reaction is found to be dependent only upon the concentration of the alkyl halide the reaction is first order. The substitution reaction is thus termed SN1, and the elimination reaction is termed E1. These reactions are unimolecular and occur in two steps. The first step is rate-limiting and involves the loss of the leaving group to form a carbocation. In the second, fast, step the nucleophile adds to the carbocation in the SN1 reaction or elimination occurs to give an alkene in the E1 reaction. Because the carbocation is planar, the nucleophile can add to either face and therefore racemization is usually observed although solvent effects can influence this somewhat. E1 elimination follows Zaitsev’s rule and typically yields the most substituted alkene as the major product. Conditions which favor the SN1/E1 pathway include the use of a weak…arrow_forward
- Alkyl halides undergo nucleophilic substitution and elimination reactions. When the kinetics of the reaction are measured, if the rate of the reaction is found to be dependent only upon the concentration of the alkyl halide the reaction is first order. The substitution reaction is thus termed SN1, and the elimination reaction is termed E1. These reactions are unimolecular and occur in two steps. The first step is rate-limiting and involves the loss of the leaving group to form a carbocation. In the second, fast, step the nucleophile adds to the carbocation in the SN1 reaction or elimination occurs to give an alkene in the E1 reaction. Because the carbocation is planar, the nucleophile can add to either face and therefore racemization is usually observed although solvent effects can influence this somewhat. E1 elimination follows Zaitsev’s rule and typically yields the most substituted alkene as the major product. Conditions which favor the SN1/E1 pathway include the use of a weak…arrow_forwardHeterocyclic compounds can undergo nitration reactions with some regioselectivity, giving products in majority. From the following reaction give the raw material from which it is formed and the mechanism under which the transformation takes place.arrow_forwardGive the major organic products from the following reactionsarrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage LearningOrganic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning