Let's suppose the tetrahedral Alkoxide Ion is as given below in reaction (*).
In this reaction the starting carboxylic acid derivative is Benzoyl Chloride.
Benzoyl Chloride when reacted with Methaneamine forms Tetrahedral Alkoxide Ion, The negative charge migrates to carbon forming double bond and the chloride ion (good leaving group) leaves and abstract proton from Nitrogen atom to neutralize it.
So,
The Final product is Methylbenzamide (Amide) which is also a derivative of carboxylic acid.
Reaction is shown below,
