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: AIM : To report a case of optic and peripheral neuropathy after chronic use of disulfiram for alcohol dependence management .
### Output Text:
AIM : To report a case of optic and peripheral neuropathy after chronic use of <span class="chemical">disulfiram</span> for alcohol dependence management . 