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Reimer Tiemann Reaction

a Write a sho...

Question

a) Write a short note on Reimer- Tiemann reaction.
b) Two isomeric compounds (A) and (B) have molecular formula $C_{7} H_{7} O H$ (A) gives violet colour with neutral ferric chloride solution whereas (B) does not. Suggest structures for (A) and (B)

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Solution

a) Reimer-Tiemann reaction: When the phenol is treated with chlorophyll in presence of aqueous sodium or potassium hydroxide at 340 K followed by hydrolysis of the resulting product gives 2-hydroxybenzaldehyde as the major product. This reaction is called the Reimer-Tiemann reaction.
b) In the above image, structure (1) is A and structure (2) is B. We can see that the structure(1) has Oh group directly attached to the aromatic ring creating an " enol" system which shows violet colour with ferric chloride solution while the benzyl alcohol will not show any reaction with the solution.

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Q. An organic compound (A) of molecular formula

C_{6} H_{6} O

gives violet colour with neutral ferric chloride. Compound (A) when heated with zinc dust gives a hydrocarbon (B). Also compound (A) reacts with phthalic anhydride and conc.

H_{2} S O_{4}

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C_{20} H_{14} O_{4}

. Identify (A), (B) and (C). Explain the reactions.

(A), (B)

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are three non-cyclic functional isomers of a carbonyl compound with molecular formula

C_{4} H_{8} O

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give positive Tollen's test whereas isomer

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(B)

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Write the structures of

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Q. (a) An organic compound (A) of molecular formula

C_{6} H_{6} O

gives violet colour with neutral ferric chloride. Compound (A) when refluxed with

C H {C l}_{3}

N a O H

gives two isomers (B) and (C). Compound (A) when added ot diazomethane in alkaline medium gives an ether (D). Identify (A), (B), (C) and (D). Explain the reactions.

(b) Compound (A) is an orange red crystal and also a powerful oxidising agent. Compound (A) when treated with potassium chloride and concentrated sulphuric acid evolves coloured gas (B). When

K O H

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Q. An organic compound (A) with molecular formula

C_{8} H_{8} O

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C_{7} H_{5} O C l

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R_{2} C d

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Q. Two isomeric compounds

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B

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C_{3} H_{6} C l_{2}

K O H

solution, A gives propionaldehyde and

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A

B

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