GPR84 receptor antagonist and use thereof

A compound or a pharmaceutically acceptable salt having the structure of formula I,

• wherein,
• Y is O or S;
• Z is H, or an ion of the following metal:
• L1, Na, K, Ca, Mg, Cu, Fe, Zn, Al, Mn, or a conjugated acid of the following base:
• NH3, arginine, betaine, caffeine, choline, N,N′-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol, aminoethanol, ethanolamine, ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucosamine, aminoglucose, histidine, hydroxycobalamin, isopropylamine, lysine, methyl glucosamine, morpholine, piperazine, piperidine, polyamine resin, procaine, purine, theobromine, triethylamine, trimethylamine, tripropylamine, trometamol;
• L3 and L6 are each O;
• each of rings A, B, C, and D is independently a benzene ring or a thiophene ring;
• R1, R2, R3, and R4 are each independently 1 to 4 substituents on rings A, B, C, and D, and each substituent is independently absent, hydroxyl, mercapto, amino, F, Cl, Br, I, —CrH2r-L7-CsH2s+1, —CrH2r—N(CtH2t+1)—CsH2s+1, substituted or unsubstituted C1-C6 alkyl, the above substitution means there is one or more substituents selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, halogen, hydroxyl, amino, —COOC1-C6 alkyl, —COOH;
• L7 is each independently O, S, NH, each r is independently an integer of 0-6, each s is independently an integer of 0-6, and each t is independently an integer of 1-6;
• L2 and L5 are each independently absent or CH;
• L1 and L4 are each independently absent, CH, O, S, SO, SO2, —CH═CH—, CO, —C(═CH2)—, substituted or unsubstituted C1-C6 alkylidene, —NH—, —N(C1-C4 alkyl)-, said “substituted” means that there is one or more substituents selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, halogen, hydroxy;
• represents a single bond or a double bond.