Cyclohexanesulfonyl derivatives as GlyT1 inhibitors to treat schizophrenia

A compound of formula I:

• wherein:
• R1 is —(CH2)n—R1a, wherein n is independently 0-6, and R1a is selected from the group consisting of:
• (1) C1-6alkyl, which is unsubstituted or substituted with 1-6 halogen, hydroxy,
• (2) phenyl substituted with R2a, R2b and R2c,
• (3) C3-6cycloallyl, which is unsubstituted or substituted with C1-6alkyl, 1-6 halogen, hydroxy or —NR10R11,
• (4) —O—C1-6alkyl, which is unsubstituted or substituted with 1-6 halogen, hydroxy or —NR10R11,
• (5) —CO2R9,
• wherein R9 is independently selected from:
• (a) hydrogen,
• (b) —C1-6alkyl, which is unsubstituted or substituted with 1-6 fluoro,
• (c) benzyl, and
• (d) phenyl,
• (6) —NR10R11,
• wherein R10 and R11 are independently selected from:
• (a) hydrogen,
• (b) —C1-6alkyl, which is unsubstituted or substituted with hydroxy, 1-6 fluoro or —NR12R13, where R12 and R13 are independently selected from hydrogen and —C1-6alkyl,
• (c) —C3-6cycloalkyl, which is unsubstituted or substituted with hydroxy, 1-6 fluoro or —NR12R13,
• (d) benzyl,
• (e) phenyl, and
• (7) —CONR10R11;
• R2 is selected from the group consisting of:
• (1) phenyl, which is substituted with R2a, R2b and R2c,
• (2) C1-8alkyl, which is unsubstituted or substituted with 1-6 halogen, hydroxy, —NR10R11, phenyl or heterocycle, where the phenyl or heterocycle is substituted with R2a, R2b and R2c,
• (3) C3-6cycloalkyl, which is unsubstituted or substituted with 1-6 halogen, hydroxy or —NR10R11, and
• (4) —C1-6alkyl-(C3-6cycloalkyl), which is unsubstituted or substituted with 1-6 halogen, hydroxy or —NR10R11;
• R2a, R2b and R2c are independently selected from the group consisting of:
• (1) hydrogen,
• (2) halogen,
• (3) —C1-6alkyl, which is unsubstituted or substituted with:
• (a) 1-6 halogen,
• (b) phenyl,
• (c) C3-6cycloalkyl, or
• (d) —NR10R11,
• (4) —O—C1-6alkyl, which is unsubstituted or substituted with 1-6 halogen,
• (5) hydroxy,
• (6) —SCF3,
• (7) —SCHF2,
• (8) —SCH3,
• (9) —CO2R9,
• (10) —CN,
• (11) —SO2R9,
• (12) —SO2—NR10R11,
• (13) —NR10R11,
• (14) —CONR10R11, and
• (15) —NO2;
• R3 is selected from the group consisting of:
• (1) C1-6alkyl, which is unsubstituted or substituted with 1-6 halogen, hydroxyl, or —NR10R11,
• (2) C3-6cycloalkyl, which is unsubstituted or substituted with 1-6 halogen, hydroxyl or —NR10R11,
• R4 and R5 are independently selected from the group consisting of:
• (1) hydrogen, and
• (2) C1-6alkyl, which is unsubstituted or substituted with halogen or hydroxyl, or R4 and R5 taken together form a C3-6cycloalkyl ring;
• A is selected from the group consisting of:
• (1) —O—, and
• (2) —NR10—;
• m is zero or one, whereby when m is zero R2 is attached directly to the carbonyl;
• and pharmaceutically acceptable salts thereof and individual enantiomers and diastereomers thereof.