question_answer

\[R-CH=C{{H}_{2}}+CO+{{H}_{2}}\]\[\xrightarrow[high\text{ }pressure]{High\,\,tem}RC{{H}_{2}}C{{H}_{2}}CHO\] The above reaction is:

A)  Mendius reaction

B)  Oxo process

C)  Sandmeyer reaction

D)  Stephens reaction

Correct Answer: B

Solution :

(i) Mendius reaction: In this reaction organic nitrile is reduced to \[{{1}^{o}}\] amine by nascent hydrogen. \[\underset{alkyl\text{ }nitrile}{\mathop{RCN}}\,\,\,+2[H]\xrightarrow{Ni/Pt}\underset{{{1}^{o}}amine}{\mathop{RC{{H}_{2}}N{{H}_{2}}}}\,\] (ii) Sandmeyer reaction: In this reaction diazonium salt reacts with \[CuCl\] or \[CuBr\] to form chloro or bromo substituted aromatic compounds. (iii) Stephens reduction: \[R-C\equiv N+2[H]+HCl\xrightarrow[ether]{SnC{{l}_{2}}\And HCl}\] \[RCHO+N{{H}_{4}}Cl\] It is method of preparation of aldehydes by reduction nitriles by \[SnC{{l}_{2}}\] and \[HCl\]. (iv) Oxo process: It is method of preparation of aldehydes having one carbon atom more than parent alkene by its reaction with CO and \[{{H}_{2}}\]. \[RCH=C{{H}_{2}}+CO+{{H}_{2}}\xrightarrow[high\text{ }pressure]{High\,\,\,temp.\,\,\And }\] \[RC{{H}_{2}}C{{H}_{2}}CHO\]