Как через выбранный option добавить атрибут select?

$(document).on('change', '.select', function(){ 
  if($(this).val() == 'option4') { 
    $(this).attr('name', 'select_name'); 
  } 
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 
<select class="select"> 
  <option selected disabled>Выберите</option> 
  <option value="option1">option1</option> 
  <option value="option2">option2</option> 
</select> 
<br /> 
<select class="select"> 
  <option selected disabled>Выберите</option> 
  <option value="option3">option3</option> 
  <option value="option4">option4</option> 
</select>