A process A for the production of compounds of formula I is provided. Process A includes Step A of reacting compounds of formula II with 2,3-dihalopropionitrile or 2-haloacrylonitrile in the presence of DIPEA. A process B for the production of compounds of formula III is also provided. Process B includes Step B of reacting compounds of formula I with Br2 in the presence of DIPEA. A process C for the production of compounds of formula IV is further provided. Process C includes Step C of reacting compounds of formula III with di(C1-C4-alkoxy)methane and either POCl3, or a mixture comprising POCl3 and DMF, in the presence of DIPEA. Additionally, the use of DIPEA as a base in the production of compounds of formula I, compounds of formula III, or compounds of formula IV is provided.