If you have an existing space, why not consider leveraging the current tenants for part of the money needed?
Spend some money (tenants can pitch in for that instead) in a fundraising party! Invite local band, caterer (ask for discount in exchange of promotion) have some context for the event such as idea pitching, or brownbag, etc... as the main entertainment... sell tickets for that event. Might not give you all you need but will help get there. _ aim for double what you spend at a minimum!

Try gofundme.com

Get in the news and ask for community support.

Get infront of the local development offices ans ask for grants (this is common) as it helps development.

These are just some ideas. best of luck

I'm a big advocate of business development partnerships in situations like this. There's "fundraising" from a capital perspective, and then there's growing a business through revenue or partnerships. Maybe there are good ways to think about your client from that perspective? Perhaps there are reasons that US investors or partners want to get involved with a Brazilian company? Maybe there is value that can be transacted across that channel that could lead to enhanced revenue to be specifically allocated to US expansion?

With the proliferation of coworking I think it's all about the story of how yours is different from not just the user/buyer perspective, but from enhanced sources of revenue. Is it really just a Real Estate play or is there something for the investor to chew on that gives this a distinction from other options in the space, who are also seeking expansion capital.

Happy to discuss with you on a call. :)

Brazil is a difficult country due to its complex tax structure. However, Brazil is huge in software development and tech ventures; so I would recommend reaching out to some PEs or VCs that already invest in this sector and are open to save some bucks in office space by leveraging on the coworking space you offer. Also, there are many US companies that have just sales individuals in Latin America or Brazil; so reaching out to those companies through a marketing campaign linking US companies with US Realtors offering a guaranteed space with their initial investment could increase your cash flow to start building up offices. Hope this helps.