4-Chloro-5-amino-2-phenyl-3(2H)-pyridazinone (I) is treated with Pd/C/NaBH4 to give 5-amino-2-phenyl-3(2H)-pyridazinone (II), which is O-methylated with dimethylsultate to LU-1631.

The Mezinium Methyl Sulfate is an organic compound with the formula C₁₁H₁₂N₃O^.CH₃O₄S. The IUPAC name of this chemical is 6-methoxy-1-phenylpyridazin-1-ium-4-amine; methyl sulfate. With the CAS registry number 30578-37-1, it is also named as 4-Amino-6-methoxy-1-phenylpyridazin-1-ium methyl sulfate. The product's classification codes are Antihypotensive; Drug / Therapeutic Agent; Reproductive Effect.

Physical properties about Mezinium Methyl Sulfate are: (1)#H bond acceptors: 4; (2)#H bond donors: 2; (3)#Freely Rotating Bonds: 3; (4)Polar Surface Area: 29.24 Å².

You can still convert the following datas into molecular structure:
(1)SMILES: [O-]S(=O)(=O)OC.O(c1[n+](ncc(N)c1)c2ccccc2)C
(2)InChI: InChI=1/C11H11N3O.CH4O4S/c1-15-11-7-9(12)8-13-14(11)10-5-3-2-4-6-10;1-5-6(2,3)4/h2-8,12H,1H3;1H3,(H,2,3,4)
(3)InChIKey: ZEASXVYVFFXULL-UHFFFAOYAG
(4)Std. InChI: InChI=1S/C11H11N3O.CH4O4S/c1-15-11-7-9(12)8-13-14(11)10-5-3-2-4-6-10;1-5-6(2,3)4/h2-8,12H,1H3;1H3,(H,2,3,4)
(5)Std. InChIKey: ZEASXVYVFFXULL-UHFFFAOYSA-N