The time difference varies from 0 to 2 hours. Sao Paulo uses Brasilia Time (BRT, UTC-3) while Santiago uses Chile Standard Time (CLT/CLST, UTC-4/-3). When it's 12:00 PM in Sao Paulo, it's typically 11:00 AM or 12:00 PM in Santiago.
Brazil no longer observes daylight saving time (since 2019), while Chile does. This causes the difference to vary throughout the year.
Any time during business hours works! With a difference of at most 2 hours, you can easily coordinate calls during normal working hours (9:00 AM - 6:00 PM).
Sao Paulo and Santiago are both major South American business centers. They're connected by direct flights taking about 4 hours, facilitating significant trade and investment between Brazil and Chile.