Disclosed is a compound of Formula I: ##STR1## or a pharmaceutically acceptable salt or solvate thereof. Also disclosed are pharmaceutical compositions comprising a pharmaceutically acceptable carrier and an effective amount of a Compound of Formula I.Further disclosed is a method of treating allergy (for example asthma), inflammation, hypertension, raised intraocular pressure (such as glaucoma)--i.e., a method of lowering intraocular pressure, sleeping disorders, states of hyper and hypo motility and acidic secretion of the gastrointestinal tract, hypo and hyperactivity of the central nervous system (for example, agitation and depression) and other CNS disorders (such as Alzheimers, Schizophrenia, and migraine) comprising administering an effective amount of a compound of Formula I to a patient in need of such treatment.