select a.ID from PricebookEntry a   Product2 b where Product2.ProductCode =:productCode    

error is appeared.

unexpected token: Product2 

how can i make the SOQL[select a.ID from PricebookEntry a   Product2 b where Product2.ProductCode =:productCode ] to be right?

// List of Lead IDs
  List<ID> leadIDs = new ID[] {};
  
  // List to hold the leads that will be updated 
  List<Lead> leadsToUpdate = new Lead[] {};
  // List to hold the Contacts that changed and have an open & active account now
  List<Contact> ContactwithAccount = new Contact[] {};
  //Map of Contacts, indexed by matching lead ids - added 03/04/08 SH
  Map<ID, Contact> cMap = new Map<ID, Contact>();

  // Loop through all the incoming contacts and get the lead ID
  for(Integer j = 0; j<Trigger.new.size(); j++) {
//If the lead__c change from a value null to a value not null we have to look for the lead that marches the contact and update the lead 
    if (Trigger.new[j].Lead__c != null && Trigger.old[j].Lead__c == null){
       ContactwithAccount.add(Trigger.new[j]);
       leadIDs.add(Trigger.new[j].Lead__c);
            //insert matching contact info into map - added 03/04/08 SH
            cMap.put(Trigger.new[j].Lead__c, Trigger.new[j]);
    }     
  }    


  // issue one query to get all leads for all incoming IDs and store in map (to avoid Apex restrictions)
  Map<ID, Lead> matchingLeads = new Map<ID, Lead> ([SELECT Id, Status, MMB__c, Market_Update__c FROM Lead WHERE status = 'Open' and id IN :leadIDs]);
  // loop through the incoming contacts again, for each, get the lead from the map
  for(Contact loopContact : ContactwithAccount){
      Lead foundLead = matchingLeads.get(loopContact.Lead__c);
      if(foundLead!=null){
          foundLead.Status = 'Converted';
          foundLead.Date_Converted__c = System.today();
          leadsToUpdate.add(foundLead); 
      }
    
  }
  // finally update any leads that have been marked for update  
  update leadsToUpdate;

    //empty Lists for updated objects - added 03/04/08 SH
    List<Event> updateE = new List<Event>();
    List<Task> updateT = new List<Task>();
    List<Note> insertN = new List<Note>();
    List<Note> deleteN = new List<Note>();
    List<Attachment> insertA = new List<Attachment>();
    List<Attachment> deleteA = new List<Attachment>();
    List<CampaignMember> insertCM = new List<CampaignMember>();
    List<CampaignMember> deleteCM = new List<CampaignMember>();

    //loop through lead events and assign them to corresponding contact from cMap - added 03/04/08 SH
    for (Event[] arre : [Select Id, WhoId from Event where WhoId IN :matchingLeads.KeySet()]) {
       for(Event e : arre){
        e.WhoId = cMap.get(e.WhoId).Id;
        updateE.add(e);
        }
    }
    update updateE;

    //loop through lead tasks and assign them to corresponding contact from cMap - added 03/04/08 SH
    for (Task[] arrt : [Select Id, WhoId from Task where WhoId IN :matchingLeads.KeySet()]) {
       for(Task t : arrt){
        t.WhoId = cMap.get(t.WhoId).Id;
        updateT.add(t);
        }
    }
    update updateT;

    //loop through campaign member records for lead and recreate for contact, then delete lead version
    for (CampaignMember[] arrcm : [Select Id, ContactId, LeadId, CampaignId, Status from CampaignMember where LeadId IN :matchingLeads.KeySet()]) {
     for(CampaignMember cm : arrcm){
        CampaignMember cmNew = new CampaignMember(CampaignId = cm.CampaignId, ContactId = cMap.get(cm.LeadId).Id, Status = cm.Status);
        insertCM.add(cmNew);
        deleteCM.add(cm);
     }
    }
    insert insertCM;
    delete deleteCM;

    for (Note[] arrn : [Select Body, Id, IsPrivate, OwnerId, ParentId, Title from Note where ParentId IN :matchingLeads.KeySet()]) {
      for(Note n : arrn){
        Note nNew = new Note(Body = n.Body, IsPrivate = n.IsPrivate, OwnerId = n.OwnerId, Title = n.Title, ParentId = cMap.get(n.ParentId).Id);
        insertN.add(nNew);
        deleteN.add(n);
      }
    }
    insert insertN;
    delete deleteN;

    for (Attachment[] arra : [Select Id, Body, BodyLength, ContentType, IsPrivate, Name, OwnerId, ParentId from Attachment where ParentId IN :matchingLeads.KeySet()]) {
      for(Attachment a : arra){
        Attachment aNew = new Attachment(Body = a.Body, ContentType = a.ContentType, IsPrivte = a.IsPrivate, Name = a.Name, OwnerId = a.OwnerId, ParentId = cMap.get(a.ParentId).Id);
        insertA.add(aNew);
        deleteA.add(a);
      }
    }
    insert insertA;
    delete deleteA;
}