Question

Correct sequence of reagent for the given reaction:

• A. NaOEt, B$_2$H$_6$/H$_2$O/Jones' reagent
• B. B$_2$H$_6$/H$_2$O/Jones' reagent, NaOEt
• C. aq. KOH, B$_2$H$_6$/H$_2$O/Jones' reagent
• D. NaOEt, Hg(OAc)$_2$/H$_2$O/Jones' reagent

Hint:

For converting aryl halides to carboxylic acids, a sequence of reduction followed by oxidation is commonly used, with B$_2$H$_6$/H$_2$O for reduction and Jones' reagent for oxidation.

Answer 1

The Correct Option is A

Step 1: Reaction details.
The reaction involves the conversion of a bromo-substituted benzene (Br-C$_6$H$_5$) to benzoic acid (C$_6$H$_5$COOH). This is typically achieved by using reagents that can replace the bromine with a carboxyl group.
Step 2: Reagents used.
- First, NaOEt is used to prepare an intermediate that can undergo reduction. - B$_2$H$_6$/H$_2$O reduces the intermediate, and finally, Jones' reagent (CrO$_3$ in aqueous H$_2$SO$_4$) oxidizes the intermediate to the carboxylic acid.
Step 3: Conclusion.
Thus, the correct reagent sequence is NaOEt, B$_2$H$_6$/H$_2$O, followed by Jones' reagent, which corresponds to option (1).