In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Reversal of neuroleptic - induced catalepsy by novel aryl - piperazine anxiolytic drugs .
### Output Text:
Reversal of neuroleptic - induced catalepsy by novel <span class="chemical">aryl - piperazine</span> anxiolytic drugs . 