Über die 2-(1,2,3,4-Tetrahydro-4,4,6-trimethyl-2-thioxopyrimidin-1)-benzoesäure und das 2,3,4,4a-Tetrahydro-3,3,4a-trimethyl-1-thioxo-1H, 6H—pyrimido[1,6-a][3,1]-benzoxazin-6-on Über Heterocyclen, 55. Mitt.

Dimethyloxobutylisothiocyanate1 reacts with anthranilic acid to a mixture of much pyrimidobenzoxazine5 a and less tetrahydrothioxopyrimidinebenzoic acid3 a (and tautom.4 a resp.). By treatment with methanolic KOH solution5 a is converted into3 a, 4 a. At refluxing temperature3 a, 4 a, and5 a resp., are rearranged inDMF into thioxopyridineanthranilic acid7 a, thioxopyridineanthranilic dimethylamide7 d and dimethylaminodihydro-2(1H)-pyridinethione8. Also pyridineanthranilates7b, c and pyridineanthranilic nitrile12 are formed from pyrimidinebenzoic esters3 b, 4 b, 3 c, 4 c and pyrimidinebenzoic nitrile10, 11 resp., by boiling inDMF. The reaction of1 with methyl anthranilate leads to7 b and triazapentaphene9. o-Aminobenzoic nitrile HCl reacts with1 to pyrimidinequinazoline5 b.