Phenylhydrazine, 97%, Thermo Scientific Chemicals

General References:

1. Derivatizing agent for the conversion of carbonyl compounds to their phenylhydrazones best known as intermediates in the Fischer indole synthesis, by cyclization under acidic conditions with loss of ammonia. The classical reagent is anhydrous ZnCl₂: Org. Synth. Coll., 3, 725 (1976). For reviews, see: Chem. Rev., 63, 373 (1963); 69, 227 (1969); Tetrahedron, 36, 161 (1980); Org. Prep. Proced. Int., 25, 609 (1993). Milder cyclization conditions are sometimes effective, e.g.: dilute H₂SO₄: J. Org. Chem., 59, 3738 (1994); PCl₃: J. Chem. Soc., Chem. Commun., 563 (1981); Tetrahedron, 41, 4615 (1985). Cyclohexanone phenylhydrazone gives tetrahydrocarbazole on heating in acetic acid: Org. Synth. Coll., 4, 884 (1963).
2. Methods used for the cleavage of phenylhydrazones include exchange by refluxing with acetone: J. Org. Chem., 40, 3302 (1975), or oxidative cleavage by Fe(NO₃)₃ on a clay support: Synthesis, 439 (1985).
3. Wang, L.; Wang, P.; Liu, Y.; Zheng, L.; Sun, Q.; Qiu, S.; Liu, C. Effects of phenylhydrazine-4-sulfonic acid on the reduction of GO and preparation of hydrophilic graphene with broad pH stability and antioxidant activity. RSC Adv. 2015, 5 (48), 38696-38705.
4. Gein, V. L.; Mar’yasov, M. A. Reactions of 5-aryl-4-(hetaren-2-ylcarbonyl)-3-hydroxy-1-(1, 3-thiazol-2-yl)-2, 5-dihydro-1H-pyrrol-2-ones with hydrazine, phenylhydrazine, and hydroxylamine. Russ. J. Org. Chem. 2015, 51 (1), 110-115.