The following code has been taken from https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/langCon_apex_dml_examples_merge.htm 

// Create master account
Account master = new Account(Name='Account1');
insert master;

// Create duplicate accounts
Account[] duplicates = new Account[]{
    // Duplicate account 
    new Account(Name='Account1, Inc.'),
    // Second duplicate account
    new Account(Name='Account 1')
};
insert duplicates;

// Create child contact and associate it with first account
Contact c = new Contact(firstname='Joe',lastname='Smith', accountId=duplicates[0].Id);
insert c;


// Merge accounts into master
Database.MergeResult[] results = Database.merge(master, duplicates, false);

for(Database.MergeResult res : results) {
    if (res.isSuccess()) {
        // Get the master ID from the result and validate it
        System.debug('Master record ID: ' + res.getId());
        System.assertEquals(master.Id, res.getId());                
        
        // Get the IDs of the merged records and display them
        List<Id> mergedIds = res.getMergedRecordIds();
        System.debug('IDs of merged records: ' + mergedIds);                
        
        // Get the ID of the reparented record and 
        // validate that this the contact ID.
        System.debug('Reparented record ID: ' + res.getUpdatedRelatedIds());
        System.assertEquals(c.Id, res.getUpdatedRelatedIds()[0]);               
    }
    else {
        for(Database.Error err : res.getErrors()) {
            // Write each error to the debug output
            System.debug(err.getMessage());
        }
    }
}

I have been trying to merge duplicates accounts, but I do not know how to make the correct SELECTs queries. 
I tried this: 

public List<Account> masterAccount;//Account 1
    public List<Account> accountstomerge;//Account 1
    public void MergeTesting()
    {
        //Account masteAcc = new Account(Name = 'Boolean Master');
        Account masteAcc = [Select id, name from Account where name = 'Account 1' Limit 1];
        //insert masteAcc;
        //masterAccount = [SELECT id, name, website, phone, fax, CreatedDate FROM Account WHERE name = 'Account1'];
        accountstomerge = [SELECT id, name, website, phone, fax, CreatedDate FROM Account where name like '%Boolean%'];

        // Merge accounts into master
        
        try
        {
            Database.MergeResult[] results = Database.merge(masteAcc, accountstomerge, false);
            for(Database.MergeResult res : results) {
            if (res.isSuccess()) {
                // Get the master ID from the result and validate it
                System.debug('Master record ID: ' + res.getId());
                System.assertEquals(masteAcc.Id, res.getId());                
                
                // Get the IDs of the merged records and display them
                List<Id> mergedIds = res.getMergedRecordIds();
                System.debug('IDs of merged records: ' + mergedIds);
                
            }
            else {
                for(Database.Error err : res.getErrors()) 
                {
                    //Error message
                }
            }
        }
        }
        catch(Exception e)
        {
            System.debug('The following error: ' + e.getMessage());
        }

But there is no succed. Does anyone know what should be the correct syntax on these scripts to merge accounts successfully?