97315-90-7

Upstream product

• 110-89-4 piperidine 
• 41071-37-8 (Z)-O-methyl-4-nitrobenzohydroximoyl chloride 

Downstream Products

• 97315-96-3 (4-Nitro-phenyl)-piperidin-1-yl-methanone O-methyl-oxime 

Relevant academic research and scientific papers

MECHANISM OF BIMOLECULAR SUBSTITUTION REACTIONS OF HYDROXIMOYL HALIDES WITH AMINES IN ACETONITRILE SOLUTION

The reaction in acetonitrile solution of (Z)-O-methylbenzohydroximoyl chlorides with morpholine, pyrrolidine and azetidine gives the corresponding (Z)-amidoximes in acetonitrile.The rates of these reactions were measured under pseudo-first-order conditions (excess amine).The reactions were found to follow overall second-order kinetics (first order in amine).The Hammett ρ-value (with ?) for the reaction with pyrrolidine is +0.92.The reaction of the p-nitro compound with pyrrolidine gives a significant element effect .A Broens ted β-value of 0.38 was estimated from the reactions of morpholine and piperidine with the p-nitrohydroximoyl chloride.The slower reaction of (E)-O-methyl-p-nitrobenzohydroximoyl chloride with azetidine gives primarily the (E)-amidoxime (E:Z ca. 98:2).This reaction also follows second-order kinetics.The kinetic observations made in this study are compared with the corresponding results obtained in earlier work in benzene solution.It is suggested that in acetonitrile solution the reactions proceed by an addition-elimination mechanism with rate-determining loss of chloride ion (AN + DN*).It is furthe suggested that acetonitrile is assisting in the breakdown of the tetrahedral intermediates formed in these reactions.

Mechanisms and Stereochemistry of Amine Substitution Reactions at the Carbon-Nitrogen Double Bond

The reaction of (Z)-O-methyl-p-nitrobenzohydroximoyl chloride with morpholine, piperidine, pyrrolidine, and azetidine gives the corresponding (Z)-amidoximes .The rate equations for these reactions in benzene solution contain both first-order and second-order terms in amine.The rates of these reactions increase with increasing basicity k(morpholine)> and decreasing size of amine k(pyrrolidine) > k(piperidine)>.The approximate Hammett ρ-values for the reaction of (Z)-hydroximoyl chlorides with azetidine are +1.0 for the amine-catalyzed process and 0 for the uncatalyzed pathway.The element effect, k(p-nitrobenzohydroximoyl bromide)/k(p-nitrobenzohydroximoyl chloride), is 11.9 for the amine-catalyzed reaction and 8.16 for the uncatalyzed reaction.These results suggest that the reactions proceed by an addition-elimination mechanism (AN + DN) in which the amine is deprotonating the zwitterionic tetrahedral intermediate in the amine-catalyzed process.The slow reaction of azetidine in benzene solution with (E)-O-methyl-p-nitrobenzohydroximoyl chloride gives a mixture of the (Z)- and (E)-amidoxime with the E isomer predominating (E/Z ca. 98:2).The rate equation for this reaction contains first-order and third-order terms in azetidine.It is suggested that the amine-catalyzed route involves nucleophilic attack by an amine monomer to form a tetrahedral intermediate which breaks down with the assistance of an amine dimer (or the homoconjugate acid of the amine).The difference in the observed rate equations for (Z)- and (E)-hydroximoyl chlorides with azetidine is attributed to stereoelectronic effects.

Mechanism of Amine and Amide Ion Substitution Reactions at the Carbon-Nitrogen Double Bond.

Reactions of the (Z)-hydroximoyl chlorides 3a-e with secondary amines without solvent at 32 deg C for 24 h give high yields of (Z)-benzamidoximes 7a-f.Although the amidoximes 7a-f do not isomerize under the reaction conditions, they isomerize to the E iso