Benzaldehyde thiosemicarbazone

Benzaldehyde thiosemicarbazone [MCl4(PhCH=NNHCSNH2)] S and azomethine N 4... 

Amino-5-phenyl-l,3,4-thiadiazole is reduced by sodium amalgam to benzaldehyde thiosemicarbazone, but the 5-H and 5-methyl analogs do not react (68AHC(9)165, p. 197) (see also Scheme 9 for LAH reduction). 

Acetylation of benzaldehyde thiosemicarbazone (165) yields the thiadiazoline (166) and not the diacyl derivative (167) as previously suggested (Scheme 18). Structural proof rests on spectroscopic data and on oxidation to the thiadiazole (168) followed by deacetylation with hydrazine to (169). Mild acid or base hydrolysis of (166) furnishes the starting (165) while methylation gives (170), a product identical to that obtained from the acetylation of (171) (80JOC1473). 

Phenyl Bis[henzaldehyde thiosemicaihazone] Tellurium Chloride2 A solution of 1.0 g (3.2 mmol) phenyl tellurium trichloride in 30 ml methanol is added to a solution of 2.3 g (12.8 mmol) benzaldehyde thiosemicarbazone in 30 ml of warm water. The mixture is stirred for 0.5 h and then set aside for 12 h. The yellow crystals of the product arc filtered and recrystallized from methanol yield 79% m.p. 70- 72°. 

Sodium amalgam reduced 2-amino-5-phenyl-1,3,4-thiadiazole (38) to benzaldehyde thiosemicarbazone, whereas the 5-H and 5-methyl analogs were unaffected. The latter compounds could not be reduced polarographically, whereas 38 gave a half wave potential of —1.940 volts. 

Finely powdered benzoyl peroxide added all at once with stirring to a soln. of benzaldehyde thiosemicarbazone in alcohol, and stirring continued for 5-10 min. 

Benzaldehyde m-nitrophenylhydrazone Benzaldehyde phenylhydrazone Benzaldehyde semicarbazone Benzaldehyde thiosemicarbazone Benzyl ethyl ketone isonicotinoylhydrazone p-Bromophenylacetone semicarbazone p-Chloroacetophenone semicarbazone Cumyl aldehyde phenylhydrazone p-Dimethylaminobenzaldehyde m-nitro-phenylhydrazone... 

Horse heart cytochrome c (Sigma, type VI) was purified by chromatography on a Whatman CM-32 column at 4 C as described previously 24 according to the literatures 28 Pyridine aldehyde thiosemicarbazones (PATS) and benzaldehyde thiosemicarbazone (BATS) were synthesized from thiosemicarbazide and corresponding aldehydes , and recrystallized from ethanol. All other reagents were of analytical grade, and used as received. 

Irradiation of 2-methyl-4-phenyl-substituted benzaldehyde thiosemicarbazones (171) leads to the corresponding A -l,2,4-triazohne-5-thione derivatives (173) through the formation of stable 1,2,4-tria-zoHdine-5-thione derivatives (172) (Scheme 27). Irradiation of N-acylthiourea (174) in the presence of triethylamine gives thiourea (175) and benzothiazoles (176) via an electron-transfer mechanism. A photochemicaUy induced Dimroth rearrangement has been reported in the l,2-thiazolino[5.4-d]-l,2-thiazoline-3,6-dithione (177) and yields the 3ff,6ff-l,2-dithiolo[4.3-c]-l,2-dithiole (178). ... 

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