This invention relates to novel endothelin receptor antagonists, derivatives, acceptable acid addition salts, solvates, hydrates and polymorphs thereof. The invention also provides compositions comprising a compound of this invention and the use of such compositions in methods of treating diseases and conditions that are beneficially treated by compounds that block the endothelin signaling pathway that leads to vasoconstriction and in particular those diseases or conditions beneficially treated by endothelin receptor antagonists.