61044-90-4

Upstream product

• 3496-32-0 phenylketene 
• 132973-50-3 1-methoxycarbonyl-4-dimethylamino-2-thiomethyl-1,3-diazabutadiene 
• 344361-86-0 4-(dimethylamino)-2-methylsulfanyl-1,3-diazabuta-1,3-dienium iodide 
• 103-80-0 phenylacetyl chloride 

Downstream Products

• 116659-61-1 5-phenyl-2-thioxo-2,3-dihydro-1H-pyrimidin-4-one 

Relevant academic research and scientific papers

Synthesis of nitrogen bicyclic scaffolds: Pyrimido[1,2-a]pyrimidine-2,6- diones

The multi-step synthesis of 1,3,7-trisubstituted pyrimido[1,2-a] pyrimidinediones starting from isothiocyanates is described. These nitrogen bicycles were prepared by an iterative sequence of functionalization/ cyclocondensation reactions. [4+2] Cycloaddition reactions took place between diazadienic chains and various acyl chlorides providing sophisticated heterobicycles.

New 1,3-diazadienes used in heterocyclic synthesis

The synthesis of dihydropyrimidines, dihydropyrimidinones and thiadiazine-1,1-dioxides starting from neutral or cationic 2-methylthio-1,3- diazadienes is described. Addition of H2S followed by loss of methanethiol led to the corresponding thiocarbonyl compounds.

SYNTHESIS AND DIELS-ALDER REACTION OF STABLE ARYL FREE 1,3-DIAZABUTADIENE

The Diels-Alder reactions of 1-methoxycarbonyl-4-dimethylamino-2-thiomethyl-1,3-diazabutadiene with dimethyl acetylenedicarboxylate (DMAD) and monophenyl ketene give pyrimidines in one pot.

PYRIMIDONE DERIVATIVES

Compounds of the formula (I) STR1 in which R 1 and R. sub.2 each may represent hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, or alkyl, substituted by hydroxy, C 1-3 alkoxy, amino, C 1-3 alkylamino or di-C 1-3 alkylamino or R 1 and R 2 together with the nitrogen atom to which they are attached form an alicyclic heterocyclic ring which may be unsubstituted or may be substituted by one or more C 1-3 alkyl groups or a hydroxy group and/or may contain another heteroatom are described.Alk is a straight lower alkylene chain,Q is a furan or thiophen ring, the furan ring optionally bearing a further substituent R 5 adjacent to the group R 1 R 2 NAlk--or Q represents a benzene ring. R 5 represents halogen or C 1-3 alkyl which may be substituted by a hydroxy or C 1-3 alkoxy group;X represents--CH 2--,--O--or--S--;n represents zero or 1;m represents 2, 3 or 4;Y represents =O or =S;R 3 represents hydrogen in which case R 4 represents methyl or R 3 represents--(CH 2) p V(CH 2) q Ar, phenyl, or alkyl in which case R. sub.4 represents hydrogen;V represents--CH 2--,--O--, or--S--;p represents zero, 1, 2 or 3; q represents zero, 1, 2 or 3;the sum of p+q being 3 or less;Ar represents an aromatic carbocyclic or heterocyclic ring being optionally substituted by at least one C 1-3 alkyl, C 1-3 alkoxy C 1-3 alkyl, hydroxy, C 1-3 alkoxy, methylenedioxy, halogen, trifluoromethyl or di-C 1-3 alkylamino group; except that when n is zero and X is oxygen then Q represents a benzene or thiophen ring. The compounds of formula (I) have pharmacological activity as selective histamine H 2-antagonists.