5-(1-Pyrrolyl)-2-phenylthieno[2,3-d]pyrimidine as Building Block in Heterocyclic Synthesis: Novel Synthesis of Some Pyrazoles, Pyrimidines, Imidazo[1,2-a]pyrimidines, Pyrazolo[1,5-a]pyrimidines, Pyrido-(pyrimido)pyrazolo[1,5-a]pyrimidines, 1,2,4-Triazolo[1,5-a]pyrimidine and a 1,2,3,4-Tetrazolo[1,5-a]pyrimidine Derivative