Flex box how to have a static fixed column to the right of multiple flex rows?

https://codepen.io/leongaban/pen/xrdwRw

Currently CSS produces this:

What I'm trying to achieve is that flexbox still works and doesn't use floats without flexbox working

Markup

<div>
  <div class="dashboard">
    <ul class="flex-container">
      <li class="flex-item">1</li>
      <li class="flex-item">2</li>
      <li class="flex-item">3</li>
      <li class="flex-item">4</li>
      <li class="flex-item">5</li>
      <li class="flex-item">6</li>
    </ul>
    <ul class="flex-container">
      <li class="flex-item">1</li>
      <li class="flex-item">2</li>
      <li class="flex-item">3</li>
      <li class="flex-item">4</li>
      <li class="flex-item">5</li>
      <li class="flex-item">6</li>
    </ul>
  </div>

  <div class="col">

  </div>
</div>

      

        
        
        
      

    

CSS

@import "compass/css3";
// .dashboard { float: left; }
.col {
  float: right;
  width: 300px;
  height: 600px;
  background: orange;
}

.flex-container {
  display: -webkit-box;
  display: -moz-box;
  display: -ms-flexbox;
  display: -webkit-flex;
  display: flex;
  -webkit-flex-flow: row wrap;
  justify-content: space-around;
}

.flex-item {
  background: tomato;
  padding: 5px;
  width: 200px;
  height: 150px;
  margin-top: 10px;

  line-height: 150px;
  color: white;
  font-weight: bold;
  font-size: 3em;
  text-align: center;
}