The invention relates to 5-HT receptor antagonists. Novel piperidinylamino-thieno[2,3-d] pyrimidine compounds represented by Formula I, and synthesis and uses thereof for treating diseases mediated directly or indirectly by 5-HT receptors, are disclosed. Such conditions include central nervous system disorders such as anxiety, depression, schizophrenia, neural injury, stroke, and migraine. Methods of preparation and novel intermediates and pharmaceutical salts thereof are also included.