Para-chlorobenzoyl chloride

After a duration of 15-20 minutes, 15 g (0.085 mol) para-chlorobenzoyl chloride is added dropwise over a span of 10-15 minutes, and the mixture is stirred for 9 hours continuously without replenishing the ice-bath. 

A practical application of the Fischer method is found in the synthesis of the anti-inflammatory dmg indomethacin (Scheme 9.42). Hydrazone 9.82 gives the expected indole product 9.83 on acid treatment. The COOH group is protected by conversion to the t-butyl ester 9.84 employing DCC as a dehydrating agent. Ester 9.84 is subjected to benzoylation with para-chlorobenzoyl chloride and base, and the t-butyl group is removed thermally in the final reaction to give indomethacin (9.85). 

The nitro compound is also an ester which can be derived from an alcohol and an acid derivative. In this case, it would be best to synthesize the ester from the acid chloride, p-chlorobenzoyl chloride, and the amino alcohol in the presence of base. The base will prevent protonation of the amino group by the subsequently formed HCl. The nitro group can be given its proper para orientation by directly nitrating toluene. Subsequent oxidation of the methyl group and treatment with thionyl chloride will yield the acid chloride. The alcohol portion of the ester can be derived from the reaction of diethylamine with ethylene oxide. Thus, the synthetic scheme would be... 

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