When converting aniline to 1,3,5-trimethylbenzene there are 5 steps:
1. CH3COCl
2. 3CH3I/AlCl3
3. H30+/Heat
4. NaNO2/HCl
5. H3PO2

I understand step 2-4, but I forget what kind of reaction step 1 is? Is step one acylation (adding a carbonyl to an aniline)?

In case of aniline - first step is not the acylation of aromatic ring but of -NH2 group which is basic and can react with AlCl3 of the second step
LiAlH4 or Na(CH3OO)3BH/H+???
LiAlH4 is strong reducing agent and can not be used if more than one reductive groups are present.