in Wiley Online Library (wileyonlinelibrary.com).Cinnamoyl isothiocyanate 1 was reacted with 2-cyanoethanoic acid hydrazide 2 to afford 1-cyanoacetyl-4-substituted thiosemicarbazide 3, which on treatment with a mixture of glacial acetic acid and acetic anhydride gave the desired 5-cinnamoylamino-2-cyanomethyl-1,3,4-thiadiazole 4. Compound 4 was subjected to react with aromatic aldehydes, phenylisothiocyanate, carbon disulphide, and arylidene malononitrile to give coumarin 5, thiazolidines 8,9, and 1,3,4-thiadiazolo[3,2-a]pyridine 13 derivatives. The structures of all synthesized compounds were ascertained by spectral and analytical data. Antimicrobial activity of some of prepared compounds was investigated, and compounds 7, 8 were found to exhibit the highest strength.Scheme 3. Synthesis of the 1,3,4-thiadiazole derivatives 7 and 8.Scheme 2. Synthesis of 2-(2-Oxo-2H-chromen-3-yl)-5-cinnamoylamino-1,3,4-thiadiazole.

El-Azm et al., Organic Chem Curr Res 2015, 4:1 http://dx.Hydrazines with 2-acyl benzoic acids: Kirill et al. [31] reported the cyclization of 2-nitro-5-chloro phenylhydrazine27 with acyl benzoic acids 28 yielded 2-(2-nitro-5-chlorobenzene)-4-substituted phthalazin-1-ones 29 (Scheme 7).Lukacs and Simig [61] adopted a novel method for the synthesis of phthalazine derivatives 32 via the reaction of benzophenones30 with chromium (VI) oxide in a mixture of acetic anhydride and sulphuric acid followed by cyclization of the products with hydrazine hydrate in refluxing ethanol (Scheme 8).Hydrazine with 1,2-diester:The dimethylphthalate derivative 33 reacted with hydrazine to yield the desired phthalhydrazide34 which undergo chlorination with phosphorus oxychloride to give 35. Subsequent treatment with sodium methoxide afforded the methoxychloride 36 [62] (Scheme 9). Hydrazines with Phthalides: Chloroformylation of 3-methoxy benzoic acid 37 and subsequently radical bromination of 38 produced 39 in good yield. Treatment with triphenyl phosphine gave 40 and wittig olefination with 3,5-dichloro-4-pyridine carboxaldehyde 41 afforded the phthalide 42. Hydrazine cyclization of 42 resulted phthalazine derivative 43 [42] (Scheme 10). Cockcroft et al. [12] synthesized the phthalazinone derivative 47 according the following (Scheme 11). AbstractThis review highlights the methods used for the synthesis of phthalazine derivatives and fused phthalazinones. Their reactivity and synthetic importance were investigated. Phthalazine derivatives can be used as building blocks for heterocycles as well as fused heterocyclic compounds. Scheme 1: Synthesis of phthalazinone derivatives 2 and 5 Scheme 2: Synthesis of phthalazinone derivatives 7-9. Reagents and conditions: (a) CHCl 3 , reflux, 5 h, 51%; (b) hydrazinehydrate, EtOH, addition at rt and then reflux, 90˚C, 2 h, 71%; (c) MeI, KOBu t , DMF, 30 min, 80%; (d) LiOH, THF:MeOH:water (1:1:1), rt, 8-10 h, 81%. Scheme 3: Synthesis of phthalazin(2H)-1-one 11, 12 Scheme 4: Synthesis of 2-[1-(4-oxo-3,4-dihydrophthalazin-1-yl)alkyl]-1Hisoindole-1,3-(2H)-diones Scheme 5: Synthesis of 1,4-disubstituted phthalazinylpiperazine derivatives 21 Scheme 6: One-pot Synthesis of thiadiazinyl-phthalazine-1,4-diones 24 and 26 Scheme 7: Synthesis of 4-substituted phthalazin-1-ones 29. Scheme 8: Synthesis of phthalazine derivatives 32 Scheme 9: Hydrazinolysis of dimethylphthalate derivative 33 Citation: El-Azm FSMA, Mahmoud MR, Hekal MH (2015) Recent Developments in Chemistry of Phthalazines. Organic Chem Curr Res 1:132. Scheme 23: Synthesis of 1H-pyrazolo [1,2-b] phthalazin-5,10-dione derivatives 92 Scheme 24: A plausible mechanism for the synthesis of 1H-pyrazolo[1,2-b] phthalazine-5,10-diones 95 Scheme 25: Synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives 97. Scheme 28: Synthesis of 1-{[(1H-1,2,3-triazol-4-yl)methoxy]phenyl}-1Hpyrazolo[1,2-b] phthalazine-5,10-dione derivatives 104 Scheme 30: Synthesis of 2H-indazolo[1,2-b] phthalazine-triones 107 Scheme 29: Synthesis of 2H-indazolo[2,1-b]pht...

Cinnamoyl isothiocyanate 1 was reacted with 2-cyanoethanoic acid hydrazide 2 to afford 1-cyanoacetyl-4-substituted thiosemicarbazide 3 which on treatment with a mixture of glacial acetic acid and acetic anhydride gave the desired 5-cinnamoylamino-2-cyanomethyl-1,3,4-thiadiazole 4. Compound 4 was subjected to react with aromatic aldehydes, phenylisothiocyanate, carbon disulphide and arylidene malononitrile to give coumarin 5, thiazolidines 8,9 and 1,3,4-thiadiazolo[3,2-a]pyridine 13 derivatives. The structures of all synthesized compounds were ascertained by spectral and analytical data.