As used herein, unless otherwise noted, the terms “hydroxyalkyl” and “hydroxyalkoxy” are intended to include both branched and straight-chain saturated aliphatic “alkyl” or “alkoxy” groups respectively, wherein “alkyl” and “alkoxy” are as defined herein, having the specified number of carbon atoms and in which at least one hydrogen is replaced with a —OH group. The cooled mixture was concentrated under reduced pressure and the residue purified by column chromatography on silica gel eluting with EtOAc: Pet. When a moiety is described as “substituted” any number of its hydrogen atoms can be replaced, as described above. NaHCOn-BuLi (25.4 mL, 63.5 mmol, 2.5 M in hexane) was added drop wise to a −78° C. solution of 2-bromopyrazine (10.1 g, 63.5 mmol) in toluene (150 mL) under NThe title compound was prepared as a yellow oil in 25% yield from 2-methyl-N-(oxetan-3-ylidene)propane-2-sulfinamide (Preparation 51) and 2-bromopyrazine following the method described in Preparation 43. Thus, for example, “5- to 6-membered heteroaryl” refers to a heteroaryl containing from 5 to 6 atoms, including one or more heteroatoms, in the cyclic moiety of the heteroaryl. Products were generally dried under vacuum before being carried on to further reactions or submitted for biological testing. The combined organic extracts were washed with H1-Carbobenzyloxy-3-pyrrolidinone (5.0 g, 22.81 mmol) in THF (10 mL) was added to a solution of EtMgBr (15.2 mL, 45.6 mmol, 3.0 M in EtA mixture of (1-benzyl-3-ethylpyrrolidin-3-yl)methanol (104 g, 0.474 mol), ammonium formate (89.7 g, 1.42 mol) and 10% Pd/C (10 g) in MeOH (1 L) was heated under reflux for 1 hr. One skilled in the art will appreciate that isolation of a salt could be performed by mixing the free base with corresponding acid in an appropriate solvent, according to standard procedure that can be found in the literature.A solution of ethyl 2-[(pyrazin-5-ylmethyl)amino]pyrimidine-5-carboxylate (Preparation 9, 1710 mg, 6.60 mmol) in THF (13.2 mL) and MeOH (6.6 mL) was treated with a solution of LiOH.HA solution of NaOH (838 mg, 21.0 mmol) in water (10 mL) was added drop wise over 30 mins. The term urokinase, as used herein, is intended to denote both dual and single chain urokinase, the latter also being referred to herein as prourokinase. 2012 Jan. 13; 417(2):653-8).To date the only known substrate for Vanin-1 is pantetheine and it is believed that Vanin-1 acts as the predominant pantetheinase in vivo catalyzing its hydrolysis to produce pantothenic acid (vitamin B5) and cysteamine (Pitari G, et al. Up to two heteroatoms may be consecutive.The term “heteroaryl” refers to an aromatic ring structure containing from 5 to 6 ring atoms in which at least one of the ring atoms is a heteroatom (i.e., oxygen, nitrogen, or sulfur), with the remaining ring atoms being independently selected from the group consisting of carbon, oxygen, nitrogen, and sulfur. The compound of claim 14 wherein Ra, Rb, R3, R4, R5a and R5b are hydrogen; and x is 1; R1b is methyl or ethyl, optionally substituted with one, two or three fluoro, or a pharmaceutically acceptable salt thereof.16. Anti-pain agents include pregabalin, gabapentin, clonidine, neostigmine, baclofen, midazolam, ketamine and ziconotide.Accordingly, in one embodiment, the pharmaceutical combination comprises a therapeutically effective amount of a composition comprising:a first compound, the first compound being a compound of Formula I or a pharmaceutically acceptable salt thereof;a second compound being selected from an approved drug or a clinical candidate useful for the treatment of infectious or inflammatory diseases; andan optional pharmaceutically acceptable carrier, vehicle or diluent.In particular, the invention provides for a pharmaceutical combination comprising a therapeutically effective amount of a composition comprising:a first compound, the first compound being a compound of Formula I or a pharmaceutically acceptable salt thereof; anda second compound, the second compound being selected from the group consisting of antibodies or small molecules which include but are not limited to those that block the action of specific cytokines such as TNFa, IL12 and/or IL23, or inhibitors of leukocyte recruitment such as modulators of S1P receptors or integrin antagonists, or selective or non-selective inhibitors of the JAK kinases JAK1, JAK2, JAK3 and/or TYK2, inhibitors of leukocyte function such as PDE4 or SMAD7.In a specific embodiment, the invention is directed to a pharmaceutical composition of a compound of Formula I wherein the second compound is selected from Inasmuch as it may be desirable to administer a combination of active compounds, for example, for the purpose of treating a particular disease or condition, it is within the scope of the present invention that two or more pharmaceutical compositions, at least one of which comprises a compound of the invention, may conveniently be combined in the form of a kit suitable for co-administration of the compositions.