<xsd:complexType name="BaseElement">
    <xsd:attribute name="id" type="xsd:string" />
</xsd:complexType>

<xsd:complexType name="Element">
    <xsd:complexContent>
    <xsd:restriction base="BaseElement">
        <xsd:attribute name="id" type="xsd:idNewType" />
    </xsd:restriction>
    <xsd:extension base="identifiedEntityType">
           <xsd:attribute name="attr2" type="xsd:string"/>
           <xsd:attribute name="attr3" type="xsd:string"/>
          </xsd:extension>
    </xsd:complexContent>
</xsd:complexType>