3-Methyl-1-phenyl-2-pyrazoline-4,5-dione (3) condenses readily with malononitrile in refluxing ethanol to yield 4-(dicyanomethylene)-3-methyl-1-phenyl-2-pyrazolin-5-one (4). Compound 4 readily reacts with aliphatic, aromatic, and heterocyclic amines to yield 4-substituted (aminocyanomethylene)-3-methyl-1-phenyl-2-pyrazolin-5-ones (8). o-Substituted arylamines afford also 4-substituted (arylcyanomethylene)pyrazolones, which readily cyclize to give the 4-azolylidene pyrazolones 9a-c. Secondary and tertiary amines and activated phenols condense with 4 by hydrogen cyanide elimination to yield compounds 10a-c and 10a, b, respectively

3-Methyl-1-phenyl-2-pyrazoline-4,5-dione (3) condenses readily with malononitrile in refluxing ethanol to yield 4-(dicyanomethylene)-3-methyl-1-phenyl-2-pyrazolin-5-one (4). Compound 4 readily reacts with aliphatic, aromatic, and heterocyclic amines to yield 4-substituted (aminocyanomethylene)-3-methyl-1-phenyl-2-pyrazolin-5-ones (8). o-Substituted arylamines afford also 4-substituted (arylcyanomethylene)pyrazolones, which readily cyclize to give the 4-azolylidene pyrazolones 9a-c. Secondary and tertiary amines and activated phenols condense with 4 by hydrogen cyanide elimination to yield compounds 10a-c and 10a, b, respectively

Treatment of 3,4-tetramethylene-6-amino-5-cyano-thiopyran-2(1H)thione (1) with alkali followed by acidification with HCl afforded 1,2,5,6,7,8-hexahydro-4-cyano-3(2H)-oxoisoquinoline-1-thiol (2). When compound (1) was reacted with excess alkyl halides the corresponding O- and S-alkylated isoquinolines (3) were obtained. Also, -chloroacetic acid and β-bromopropionic acid reacted with compound (2) to produce thiazolo and thiazinoisoquinoiines (4) and (5). Furthermore, the reaction of (2) with one mole of phenacylbromide produced-S-phenacyl derivatives (6), which cyclized to give the corresponding thiazoloisoquinoline (7). However two moles of phenacyl bromides gave the corresponding S- and O-phenacyl derivatives (8). The later compounds were cyclized to give furoisoquinoline derivative (9).

Treatment of 3,4-tetramethylene-6-amino-5-cyano-thiopyran-2(1H)thione (1) with alkali followed by acidification with HCl afforded 1,2,5,6,7,8-hexahydro-4-cyano-3(2H)-oxoisoquinoline-1-thiol (2). When compound (1) was reacted with excess alkyl halides the corresponding O- and S-alkylated isoquinolines (3) were obtained. Also, -chloroacetic acid and β-bromopropionic acid reacted with compound (2) to produce thiazolo and thiazinoisoquinoiines (4) and (5). Furthermore, the reaction of (2) with one mole of phenacylbromide produced-S-phenacyl derivatives (6), which cyclized to give the corresponding thiazoloisoquinoline (7). However two moles of phenacyl bromides gave the corresponding S- and O-phenacyl derivatives (8). The later compounds were cyclized to give furoisoquinoline derivative (9).

Treatment of 3,4-tetramethylene-6-amino-5-cyano-thiopyran-2(1H)thione (1) with alkali followed by acidification with HCl afforded 1,2,5,6,7,8-hexahydro-4-cyano-3(2H)-oxoisoquinoline-1-thiol (2). When compound (1) was reacted with excess alkyl halides the corresponding O- and S-alkylated isoquinolines (3) were obtained. Also, -chloroacetic acid and β-bromopropionic acid reacted with compound (2) to produce thiazolo and thiazinoisoquinoiines (4) and (5). Furthermore, the reaction of (2) with one mole of phenacylbromide produced-S-phenacyl derivatives (6), which cyclized to give the corresponding thiazoloisoquinoline (7). However two moles of phenacyl bromides gave the corresponding S- and O-phenacyl derivatives (8). The later compounds were cyclized to give furoisoquinoline derivative (9).

Treatment of 3-amino-2-methyl-1(2H)-5,6,7,8-tetrahydro-thioxoisoquinoline-4-carbonitrile(2) with formamide afforded pyrimidotetrahydroisoquinoline (3). When compound 2 was reacted with halo-compounds. N-alkylation occurred to give compounds 4-6. Also, pyrimidotetrahydroisoquinolines (8-11) were obtained when oxazinotetrahydroisoquinoline (7) was treated with aminocompounds. Furthermore, base catalysed condensation of amine with aromatic aldehydes led to expected Schiff bases.12 but additional reaction at the N-methyl group with formation of styryl compound 13 was observed when the reaction was carried out in acetic acid.

Treatment of 3-amino-2-methyl-1(2H)-5,6,7,8-tetrahydro-thioxoisoquinoline-4-carbonitrile(2) with formamide afforded pyrimidotetrahydroisoquinoline (3). When compound 2 was reacted with halo-compounds. N-alkylation occurred to give compounds 4-6. Also, pyrimidotetrahydroisoquinolines (8-11) were obtained when oxazinotetrahydroisoquinoline (7) was treated with aminocompounds. Furthermore, base catalysed condensation of amine with aromatic aldehydes led to expected Schiff bases.12 but additional reaction at the N-methyl group with formation of styryl compound 13 was observed when the reaction was carried out in acetic acid.