Salt of piperidylindole compound and preparation method therefor

An acid salt of a compound as shown in general formula (I), wherein

• the compound has a structure as shown below:
• wherein:
• R1 is selected from C1-C3 alkyl or C3-C6 cycloalkyl;
• R2 is selected from C1-C3 alkyl, C1-C3 alkoxy or C3-C6 cycloalkyl;
• R3 is selected from —COOH, —C(O)NHSO2CH3 or —S(O)NHCH3;
• R4 is selected from hydrogen, halogen, C1-C3 alkyl or C1-C3 haloalkyl;
• R5 and R6 are each independently selected from halogen;
• provided that the compound as shown in general formula (I) is not
• the acid is an inorganic acid or an organic acid;
• the inorganic acid is selected from hydrochloric acid, sulfuric acid, nitric acid, hydrobromic acid, hydrofluoric acid, hydroiodic acid or phosphoric acid;
• the organic acid is selected from 2,5-dihydroxybenzoic acid, 1-hydroxy-2-naphthoic acid, acetic acid, dichloroacetic acid, trichloroacetic acid, acetohydroxamic acid, adipic acid, benzenesulfonic acid, 4-chlorobenzenesulfonic acid, benzoic acid, 4-acetylaminobenzoic acid, 4-aminobenzoic acid, decanoic acid, hexanoic acid, octanoic acid, cinnamic acid, citric acid, cyclohexaneaminosulfonic acid, camphorsulfonic acid, asparaginic acid, camphoric acid, gluconic acid, glucuronic acid, glutamic acid, isoascorbic acid, lactic acid, malic acid, mandelic acid, pyroglutamic acid, tartaric acid, dodecylsulfuric acid, dibenzoyltartaric acid, ethane-1,2-disulfonic acid, ethanesulfonic acid, formic acid, fumaric acid, galactonic acid, gentisuric acid, glutaric acid, 2-ketoglutaric acid, glycolic acid, hippuric acid, hydroxyethylsulfonic acid, lactobionic acid, ascorbic acid, aspartic acid, lauric acid, camphoric acid, maleic acid, malonic acid, methanesulfonic acid, 1,5-naphthalenedisulfonic acid, naphthalene-2-sulfonic acid, nicotinic acid, oleic acid, orotic acid, oxalic acid, palmitic acid, embonic acid, propanoic acid, salicylic acid, 4-aminosalicylic acid, sebacic acid, stearic acid, succinic acid, thiocyanic acid, undecylenoic acid, trifluoroacetic acid, benzenesulfonic acid, p-methylbenzenesulfonic acid, or L-malic acid.