public class submitDataToTargetOrg {
    public static Map<String, String> oauthCustomSettings = Utils.getCustomSettingsKeyValueMapFull('Org_Credentials');
    public static List<String> oauthCustomSettingsValues = oauthCustomSettings.values();
    public static String clientId = oauthCustomSettingsValues.get(0).subStringBetween('|ClientId : |', '|ClientId|');
    public static String clientSecret = oauthCustomSettingsValues.get(0).subStringBetween('|ClientSec : |', '|ClientSec|');
    public static String userName= oauthCustomSettingsValues.get(0).subStringBetween('|UserName : |', '|UserName|');
    public static String password= oauthCustomSettingsValues.get(0).subStringBetween('|Password : |', '|Password|');
    public static void submitDataUsingGet(List<SObject> jsonToSubmit) {

    public static void submitDataUsingGet(List<Account> accountsList) {
    Map<Id, Account> postBody = new Map<Id, Account>();
    for(Account acc : (List<Account>)jsonToSubmit) postBody.put(acc.Id, acc);
    String reqbody = 'grant_type=password&client_id='+clientId+'&client_secret='+clientSecret+'&username='+userName+'&password='+password;

    Http http = new Http();
    HttpRequest req = new HttpRequest();
    req.setBody(reqbody);
    req.setMethod('POST');
    req.setEndpoint('https://login.salesforce.com/services/oauth2/token');

    HttpResponse res = http.send(req);
    OAuth2 objAuthenticationInfo = (OAuth2)JSON.deserialize(res.getbody(), OAuth2.class);

    if(objAuthenticationInfo.access_token!=null){
        String requestBody = JSON.serialize(postBody);
        Http http2 = new Http();
        HttpRequest req1 = new HttpRequest();
        string endP = 'https://eu6.salesforce.com/services/apexrest/getAccountData';//+jsonToSubmit;
        req1.setHeader('Authorization','Bearer '+objAuthenticationInfo.access_token);
        req1.setHeader('Content-Type','application/json');
        req1.setMethod('POST');
        req1.setBody(requestBody);
        req1.setEndpoint(endP);
        HttpResponse res1 = http2.send(req1);
        //List<Account> deserializedAccounts = (List<Account>)JSON.deserialize(jsonToSubmit, List<Account>.class);
        //if (deserializedAccounts.size() > 0) Database.delete([SELECT Id FROM Account WHERE Id IN: deserializedAccounts]);
    }
}

@RestResource(urlmapping = '/getAccountData/*')
    global  class accountRestService {

    PRIVATE STATIC FINAL BOOLEAN LOG_THIS_CLASS = TRUE;

    global class requestBody {
        global List<Account> accounts;
    }

    @httpPut
    global static List<Account> populateAccountObject(accountRestService.requestBody req){
        //List<Account> deserializedAccounts = (List<Account>)JSON.deserialize(req.accounts, List<Account>.class);
        if (LOG_THIS_CLASS) System.debug('the request in populateAccountObject.. : ' + req);
        insert req.accounts;
        //String AccId = RestContext.request.params.get('AccountId');
        return req.accounts;
    }
}