import re


def extract_project_name(content):
    """
    Extract the Bazel project name from the BUILD file.

    :param str content: The Bazel BUILD file content.
    :returns: The project name, otherwise None
    :rtype: str
    """
    # extract project name
    match = re.search(
        # keyword
        r'name'
        # optional white space
        r'\s*'
        # equal assignment
        r'\='
        # optional white space
        r'\s*'
        # optional "opening" quote
        r'("?)'
        # project name
        r'([a-zA-Z0-9_-]+)'
        # optional "closing" quote (only if an "opening" quote was used)
        r'\1',
        content)
    if not match:
        return None
    return match.group(2)