Australia's Alex de Minaur eased into the second round of the Australian Open, the No.8 seed beating Dutchman Botic van de Zandschulp 6-1 7-5 6-4, but compatriot and No.25 seed Alexei Popyrin was sent packing by France's Corentin Moutet 6-4 3-6 4-6 4-6.