What would the pathway look like if the reaction started off with a four carbon haloalkane?Discuss

A mad scientist carries out an experiment. He carries out these two experiments independent of each other. Each time he performed the experiment he produced different end products.

1a) Your task is to help the scientist figure out how, ie: a reaction pathway, for the products. The scientist starts off with an “R-COOH/”, the R can be anything you want if you choose to use something in place, the final product of these crazy experiments resulted in the formation of 4-Nitrobenzyl chloride and 2-(benzylamino)-4-formyl benzoic acid, how are these made?

1b) What would the pathway look like if the reaction started off with a four carbon haloalkane?

1c) What are the pros and cons of the reaction being performed with a starting material of with the COOH versfktus the four carbon haloalkane?