| 摘要 |
<p>Poly-(5-amino-1,3,4-thiadiazol-2-yl) derivs. of general formula (I) are drug and polymer intermediates. Prepn. is by the following stages: (1) Addn. of acylisothiocyanates to bi- or poly-functional acid hydrazides to convert the hydrazide NH2 to the acylthiosemicarbazide; (2) heating this in polyphosphoric acid or other dehydrating agent cyclises the thiosemicarbazide moiety to a 1,3,4-thiadiazolyl ring giving the diacylaminoodio (1,3,4-thiadiazolyl-(2-21) cpd., from which the acyl groups may be removed by hydrolysis with acid (stage 3) to give the final product (I): (where n is 0-4 pref. 0; R is a bi- or poly-functional 1-20C (pref. 1-8C and esp. 3-6C)-aliphatic or cycloaliphatic hydrocarbon residue or a 1 or 2-ringed aromatic or heterocyclic 6-20 C residue; when n is 0, R is a chemical bond). illustrates the final product when n is 0.</p> |
