Substituted Isoindoline-1, 3-diketone PDE4 Inhibitor and Pharmaceutical Application Thereof

A compound as shown in formula V and its racemates, stereoisomers, tautomers, isotopic labels, solvates, polymorphs, esters, prodrugs or pharmaceutically acceptable salts:

• wherein each R refers to the following groups unsubstituted or optionally substituted with one, two or more Ra:
• hydrocarbyl groups of C4-C10;
• Ra is independently selected from deuterium, halogen, amino, hydroxyl, cyano, nitro, oxo;
• R1 refers to the following groups unsubstituted or optionally substituted with one, two or more R1a:
• hydrocarbyl groups of C1-C16, heteroalkyl groups of C1-C16, and cycloalkyl groups of C3-C12;
• R2 refers to the following groups unsubstituted or optionally substituted with one, two or more R2a:
• hydrocarbyl groups of C1-C16, heteroalkyl groups of C1-C16, and cycloalkyl groups of C3-C12;
• R3 refers to the following groups unsubstituted or optionally substituted with one, two or more R3a:
• hydrocarbyl groups of C1-C16, heteroalkyl groups of C1-C16, and cycloalkyl groups of C3-C12;
• R4 refers to the following groups unsubstituted or optionally substituted with one, two or more R4a:
• hydrocarbyl groups of C1-C16, heteroalkyl groups of C1-C16, and cycloalkyl groups of C3-C12;
• R1a is independently selected from deuterium, halogen, amino, hydroxyl, cyano, nitro, oxo (═O), and the following groups unsubstituted or optionally substituted with one, two or more R1b:
• hydrocarbyl groups of C1-C16, heteroalkyl groups of C1-C16, and cycloalkyl groups of C3-C12;
• R2a is independently selected from deuterium, halogen, amino, hydroxyl, cyano, nitro, oxo (═O), and the following groups unsubstituted or optionally substituted with one, two or more R2b:
• hydrocarbyl groups of C1-C16, heteroalkyl groups of C1-C16, and cycloalkyl groups of C3-C12;
• R3a is independently selected from deuterium, halogen, amino, hydroxyl, cyano, nitro, oxo (═O), and the following groups unsubstituted or optionally substituted with one, two or more R3b:
• hydrocarbyl groups of C1-C16, heteroalkyl groups of C1-C16, and cycloalkyl groups of C3-C12;
• R4a is independently selected from deuterium, halogen, amino, hydroxyl, cyano, nitro, oxo, and the following groups unsubstituted or optionally substituted with one, two or more R4b:
• hydrocarbyl groups of C1-C16, heteroalkyl groups of C1-C16, and cycloalkyl groups of C3-C12;
• R1b is selected from deuterium, halogen, amino, hydroxyl, cyano, nitro, oxo (═O), as well as hydrocarbyl groups of C1-C16, and heteroalkyl groups of C1-C16;
• R2b is selected from deuterium, halogen, amino, hydroxyl, cyano, nitro, oxo (═O), as well as hydrocarbyl groups of C1-C16, and heteroalkyl groups of C1-C16;
• R3b is selected from deuterium, halogen, amino, hydroxyl, cyano, nitro, oxo (═O), as well as hydrocarbyl groups of C1-C16, and heteroalkyl groups of C1-C16;
• R4b is selected from deuterium, halogen, amino, hydroxyl, cyano, nitro, oxo, as well as hydrocarbyl groups of C1-C16, and heteroalkyl groups of C1-C16;
• the hydrocarbyl groups are alkanes, alkenes, and alkynes;
• and the oxo is =O.