gistfile1.js

$(function () {

  Login = {};
  Login.Views = {};

  Login.Model = Backbone.Model.extend({

    //curl -v -H "Accept: application/json" -H "Content-Type: application/x-www-form-urlencoded" https://sandbox.catalogchoice.org/oauth2/access_token -d "grant_type=password&[email protected]&password=apassword&client_id=8rmz3ts4r7dvr877i2zvrsw66&scope=read write"
    url: "https://sandbox.catalogchoice.org/oauth2/access_token",

    defaults: {
      grant_type: 'password',
      client_id: '8rmz3ts4r7dvr877i2zvrsw66',
      scope: 'read write'
    }
  });

  Login.Views.Form = Backbone.View.extend({

    model: Login.Model,

    el: "#login-form",

    events: {
      "click #submit-login": function(event) {
        event.preventDefault();

        this.model = new Login.Model({
          username: this.$('#username').val(),
          password: this.$('#password').val()
        });

        //the login API doesn't support json content, so we need to use jquery directly
        $.ajax('https://sandbox.catalogchoice.org/oauth2/access_token', {
          type: 'POST',
          accepts: 'application/json',
          dconata: this.model.attributes,
          success: function (response) {
            console.log(JSON.stringify(response));
          },
          error: function (response) {
        	console.log('error');
            console.log(response);
          }

        });
      }
    }

  });

  var login = new Login.Views.Form();
});