trigger invoiceAccountInsert on invoice__c (before insert) {
   Set<String> accountNames = new Set<String>();
   Map<String, Id> accountNameToId = new Map<String, Id>();
   for(invoice__c record: Trigger.new) {
     accountNames.add(record.Account__c);
     System.debug('Account__c >>>>>>' + record.Account__c);
   }

   list<Account> acclist = new list<Account>();
   acclist = [SELECT Id, Name FROM Account WHERE Name IN :accountNames];

   for(Account acc:acclist)
   {
    accountNameToId.put(acc.Name, acc.Id);
    System.debug('acc.Name >>>>>>' + acc.Name);
    System.debug('acc.Id >>>>>>' + acc.Id);
    System.debug('accountNameToId >>>>>>' + accountNameToId);
    insert acc;
   }
}