The cas register number of Girard's Reagent P is 1126-58-5. It also can be called as Pyridinium, 1-(2-hydrazino-2-oxoethyl)-, chloride and the Systematic name about this chemical is 2-pyridin-1-ium-1-ylacetohydrazide chloride.

Physical properties about Girard's Reagent P are: (1)ACD/LogP: -5.31; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): -5.31; (4)ACD/LogD (pH 7.4): -5.31; (5)ACD/BCF (pH 5.5): 1; (6)ACD/BCF (pH 7.4): 1; (7)ACD/KOC (pH 5.5): 1; (8)ACD/KOC (pH 7.4): 1; (9)#H bond acceptors: 4; (10)#H bond donors: 3; (11)#Freely Rotating Bonds: 3; (12)Polar Surface Area: 27.43Ų.

Uses of Girard's Reagent P: 1-hydrazinocarbonylmethyl-pyridinium and 4-nitro-benzaldehyde reacts with diazomethane to get 1-[(4-nitro-benzylidenehydrazinocarbonyl)-methyl]-pyridinium. This reaction needs solvent ethanol. The yield is 67 %.

People can use the following data to convert to the molecule structure.
1.SMILES: [Cl-].O=C(NN)C[n+]1ccccc1
2.InChI: InChI=1/C7H9N3O.ClH/c8-9-7(11)6-10-4-2-1-3-5-10;/h1-5H,6,8H2;1H 
3.InChIKey: NDXLVXDHVHWYFR-UHFFFAOYAV
4.Std. InChI: InChI=1S/C7H9N3O.ClH/c8-9-7(11)6-10-4-2-1-3-5-10;/h1-5H,6,8H2;1H