Synthesis of 3‐Thiocyanato‐1H,3H‐quinoline‐2,4‐diones.

Abstract

Synthesis of 3-Thiocyanato-1H,3H-quinoline-2,4-diones. -Compounds (III) are very reactive towards nucleophiles and easily hydrolyze to the corresponding starting compounds (I). -(KLASEK*, A.; POLIS, J.; MRKVICKA, V.; KOSMRLJ, J.;

Electrochemical thiocyanation of barbituric acids

“…The reactions with BHT (2,6-di-tert-butyl-4-methylphenol) and TEMPO radical traps under the optimized conditions (Table 1, entry 11) afforded thiocyanated barbituric acid 2a in 33% and 7% yields, respectively, and low 1a conversion, which may indicate the radical nature of the discovered process (Scheme 6d). The reaction between 1a and the pre-synthesized thiocyanogen 43 produced 2a in 68% yield, supporting the idea that the thiocyanogen is a key intermediate in the discovered process (Scheme 6e).…”

Novel Tandem Hydration/Cyclodehydration of α-Thiocyanatoketones to 2-Oxo-3-thiazolines. Application to Thiazolo[5,4-c]quinoline-2,4(3aH,5H)-dione Synthesis

“…3-Alkyl/aryl-2,4-dioxo-1,2,3,4-tetrahydroquinolin-3-yl thiocyanates (2a − h) were prepared according to the procedure in the ref . For physical and spectroscopic data for compounds 2a − c , e − f , h , see ref .…”

Thermal reaction of 3aH,5H-thiazolo[5,4-c]quinoline-2,4-diones – an easy pathway to 4-amino-1H-quinolin-2-ones and novel 6H-thiazolo[3,4-c]quinazoline-3,5-diones

“…Examples of electrophilic thiocyanato group transfer to other nucleophiles have been demonstrated. 2 In wet polar solvents, compounds 2 rapidly hydrolyze back to the starting compounds 1. However, if the hydrolysis of thiocyanates of type 2 is conducted in concentrated sulfuric acid, S-(2,4-dioxo-1,2,3,4-tetrahydroquinolin-3-yl)thiocarbamates 3 are obtained, which can further cyclodehydrate to [1,3]thiazolo [5,4-c]quinoline-2,4(3aH,5H)-diones 4 (Scheme 1).…”