The present invention provides compounds of the formula which are adenosine A2B receptor antagonists and, thus, may be employed for the treatment of conditions and diseases mediated by the adenosine A2B receptor activity. Such conditions include, but are not limited to, chronic and acute inflammatory diseases involving degranulation of mast cells, e.g., asthma, allergic rhinitis and allergic dermatitis; impaired sensitivity to insulin, e.g., type 2 diabetes, pre-diabetic state, and impaired glucose tolerance; diseases in which angiogenesis is a key component of pathogenesis, e.g., solid tumors and angiogenic retinopathies; apnea of preterm infants; myocardial reperfusion injury; inflammatory bowel disease; autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, and lupus erythematosis; diseases involving microvascular abnormalities of the retina that are mediated by adenosine A2B receptors, e.g., retinopathy of prematurity, macular degeneration, and diabetic retinopathy; and cardiac diseases including hyperplasia consequent to hypertension, arteriosclerosis, and heart attack.