With the intention of, with the aim of, with a view to, to, in order to, so as to, so that, in order that.
'With the intention of', 'with the aim of', and 'with a view to'
Instead of "for the purpose of", you can use these prepositions to express purpose:
All of them are fairly formal and usually followed by a gerund.
With the aim of saving energy and reducing costs, the project manager is creating a new plan.
'In order to', 'to', 'for', and 'so as to'
"For the purpose of" is used to introduce intention, which can also be expressed by using the prepositions "so as to", "in order to", or simply "to". These are compound prepositions that have an infinitive as its object. "To" and "in order to" are quite common in written and spoken English. However, "in order to" sounds a bit more formal, and it can be used to show emphasis. So as to is less frequently used and significantly more formal.
In order to achieve your most ambitious goals, you need to overcome significant challenges.
Alternatively, when using a noun phrase, and not a verb, you can use the preposition "for" to express purpose.
James went out for a walk.
'So', 'so that', and 'in order that'
Barbara is buying some wood so that she can make a bookcase.