Ajax ignoring URL

I try to make an ajax request through JQuery triggering an onClick event, but when it sends the AJAX request I receive:

PATCH http://localhost:8000/courses 405 (Method Not Allowed) (Current page) Because it doesn’t get the URL with the id

HTML

@foreach ($courses as $course)
    <tr>
      <td>{{ Form::select('year', $years, ['class' => 'form-control'], [ 'placeholder' => $course->academicYear]) }}</td>
      <td>{{ Form::select('subject', $subjects, ['class' => 'form-control'], [ 'placeholder' => $course->subject]) }}</td>
      <td>
        <a href="" id="saveCourse" class="btn btn-success pull-left">Save</a>
        <input type="hidden" id="idCourse" value="{{ $course->id }}">
      (...)

JQUERY + AJAX

$('#saveCourse').click(function(e){
        e.preventDefault();
        var id = $('#idCourse').val();

        // Ignore this logic
        var values = {year: "", subject:"", id: id};
        var parameters = ['year', 'subject'];
        var i = 0;
        $('td > select option:selected').each(function() {
            values[parameters[i]] = $(this).text();
            i++;
        });

        // Ajax request
        $.ajax({
            type: 'patch',

            // Appending the course id here not working, 
            // but if i put anything else like /blabla/ + id ajax doesn't ignore it...

            url:  '/courses/' + id,
            headers: {'X-CSRF-Token': csrf_token},
            dataType: 'json',
            data: values,

            success: function (response) {
                console.log("SUCCESS: " + response);
            },
            error: function (reject) {
                if( reject.status === 422 ) {
                    $("#error").text("Los datos dados no cumplen el formato requerido.");
                }
            }
        });
    });

WEB.PHP

/* -----COURSE_ROUTES------ */
    Route::resource('courses', 'CourseController')->except([
        'create', 'edit'
    ]);

ROUTES

EDIT

If I use POST instead of PATCH in type AJAX gets the id.

Found a GitHub issue with the same problem https://github.com/jquery/jquery/issues/3944

Answer

I forgot to put this condition at the start of the update method in the controller… Now it works!

if(request()->ajax()) { ... }