Many substances with a broad spectrum of biological action have been observed among substituted 4,4-dimethyl [1,2]dithiolo [3,4-c]quinoline-1-thiones, and these compounds furthermore exhibit antioxidant activity and also are radical polymerization regulators [1,2]. With the aim of obtaining novel polycondensed heterocyclic systems, we have continued work on further modification of these compounds.We reported earlier [3] that acylation of 8-R-4,4-dimethyl-4,5-dihydro[1,2]dithiolo[3,4-c]quinoline-1thiones 1a-c by oxalyl chloride, as in the case of simple acyl chlorides [4], occurs exclusively at the nitrogen atom of the dihydroquinoline ring and is accompanied by spontaneous cyclization according to a Stolle reaction [5]. The best solvent in this case is absolute toluene, in which the process goes to completion within 1.5-2 h. The reaction does not require the use of Lewis acids, which are typically used as catalysts. This is possibly connected with the fact that the limiting step of the two-step Stolle reaction in the case of 8-R-4,4-dimethyl-4,5dihydro[1,2]dithiolo[3,4-c]quinoline-1-thiones 1a-f is the first acylation reaction, with formation of the corresponding intermediate chlorooxalyl amides 2a-f.As a result, derivatives of a novel condensed heterocyclic system were synthesized in good yields (60-80%): 2-R 1 -3-R 2 -7,7-dimethyl-10-thioxo-4,5,7,10-tetrahydro[1,2]dithiolo[3,4-c]pyrrolo[3,2,1-ij]quinoline-4,5-diones 3a-f (Scheme 1).Their structure is supported by the combination of IR, 1 H NMR, and mass spectral data. In the IR spectra of compounds 3a-f (Table 1), the frequencies of the stretching vibrations of the thioketone group are observed in the 1230-1240 cm -1 region, and the vibrations of the two carbonyl groups of the isatin moiety are observed at 1740-1750 cm -1 and 1760-1770 cm -1 .