NEW SYNTHESES OF HETEROCYCLES WITH VINYLC ARBODIIMIDES AND DIVINYLCARBODIIMIDES - PYRROLES, TRIAZOLES, PYRIMIDINES, PYRINDINES, ISOQUINOLINES AND THIAZOLYL-ISOTHIAZOLES

The title compounds 3 and 4 react with diazomethane either by loss or by retention of the diazo nitrogen, to afford 3,4-dihydro-2-imino-2H-p yrroles 6 and 10 or the vic-triazole 5, respectively. The structure of 5 has been established by X-ray diffraction analysis. - The [4 + 2] a ddition of benzylidene methylamine or alicyclic enamines 9 to 4 result s in the formation of partially hydrogenated pyrimidine 7, pyrindine 1 1a or isoquinoline 11b. - Thermolysis of 4 proceeds with spontaneous d ehydrogenation, giving high yields of 1-(1-indolyl) isoquinohnes 8. - The derivative 10a, when melted with sulfur, undergoes both dehydrogen ation and sulfur insertion, whereby the hitherto unknown thiazolyl-iso thiazole 13 is formed. Its structure has been elucidated by an X-ray d iffraction analysis. - A synthesis of the imidazo[2,1-a]isoquinohne de rivative 16 is reported.