Create a module with below steps:

Step 1: Create Vendor_Module.xml under

app/etc/modules/Vendor_Module.xml

<?xml version="1.0"?>
<config>
  <modules>
    <Vendor_Module>
      <active>true</active>
      <codePool>local</codePool>
      <version>0.0.1</version>
    </Vendor_Module>
  </modules>
</config>

Step 2: Create config.xml under

app/code/local/Vendor/Module/etc/config.xml

<?xml version="1.0"?>
<config>
  <modules>
    <Vendor_Module>
      <version>0.0.1</version>
    </Vendor_Module>
  </modules>
  <frontend>
       <routers>
          <brochure>
              <use>standard</use>
              <args>
                 <module>Vendor_Module</module>
                 <frontName>brochure</frontName>
              </args>
           </brochure>
       </routers>
       <layout>
            <updates>
                <vendor_module>
                    <file>brochure.xml</file>
                </vendor_module>                
            </updates>
        </layout>
    </frontend>
  <global>
    <helpers>
      <module>
        <class>Vendor_Module_Helper</class>
      </module>
    </helpers>
  </global>
</config>

Step 3: Create IndexController.php under

app/code/local/Vendor/Module/controllers/IndexController.php

<?php
class Vendor_Module_IndexController extends Mage_Core_Controller_Front_Action
{
    public function indexAction()
    {
        $this->loadLayout();
        $this->renderLayout();
    }

    public function postAction()
    {
        $post = $this->getRequest()->getPost();
        
        if ($post){
            try {
                
                // Add your mail logic here which you have used on requestBrochure.php

                Mage::getSingleton('core/session')->addSuccess('Your inquiry was submitted and will be responded to as soon as possible. Thank you for contacting us.');
                $this->_redirect('*/*/');
                return;
            } catch (Exception $e) {
                Mage::getSingleton('core/session')->addError('Unable to submit your request. Please, try again later');
                $this->_redirect('*/*/');
                return;
            }
        } else {
            $this->_redirect('*/*/');
        }
    }
}

Step 4: Create Data.php under

app/code/local/Vendor/Module/Helper/Data.php

<?php
class Vendor_Module_Helper_Data extends Mage_Core_Helper_Abstract
{
}

Step 5: Create brochure.xml under

app/design/frontend/your_package/theme/layout/brochure.xml

<?xml version="1.0"?>
<layout version="0.1.0">
    <brochure_index_index>
        <reference name="root">
            <action method="setTemplate"><template>page/1column.phtml</template></action>
        </reference>
        <reference name="content">
            <block type="core/template" name="brochure.form" as="brochure_form" template="brochure/form.phtml"/>
        </reference>
    </brochure_index_index>
</layout>

Step 6: Create form.phtml under

app/design/frontend/your_package/theme/template/brochure/form.phtml

<form action="<?php echo $this->getUrl('brochure/index/post'); ?>" id="brochureform" method="post">
    <ul class="form-list">
        <li><label>Name</label><br>
        <input class="input-text required-entry" id="name" name="name" style="width: 250px;" type="text"></li>

        <li><label>Email</label><br>
        <input class="input-text required-entry" id="email" name="email" style="width: 250px;" type="text"></li>

        <li><label>Address Line 1</label><br>
        <input class="input-text required-entry" id="address_line_1" name="address_line_1" style="width: 250px;" type="text"></li>

        <li><label>Address Line 2</label><br>
        <input class="input-text required-entry" id="address_line_2" name="address_line_2" style="width: 250px;" type="text"></li>

        <li><label>Address Line 3</label><br>
        <input class="input-text" id="address_line_3" name="address_line_3" style="width: 250px;" type="text"></li>

        <li><label>City</label><br>
        <input class="input-text required-entry" id="city" name="city" style="width: 250px;" type="text"></li>

        <li><label>Post Code</label><br>
        <input class="input-text required-entry" id="postcode" name="postcode" style="width: 250px;" type="text"></li>

        <li><label>Country</label><br>
        <input class="input-text required-entry" id="country" name="country" style="width: 250px;" type="text"></li>
    </ul><button class="form-button-alt" type="submit"><span>Submit Your Request</span></button>
</form>
<script type="text/javascript">
    //<![CDATA[
        var brochureform = new VarienForm('brochureform', true);
    //]]>   
</script>

Now you can edit the postAction according to your requirement.