Prodrugs of 4-((1r, 3s)-6-chloro-3-phenyl-2,3-dihydro-1h-inden-1-y)-1-,2,2-trimethylpiperazine and 4-((1r,3s)-6-chloro-3-(phenyl-d5)-2,3-dihydro-1h-inden-1yl)-2,2-dimethyl-1 (methyl-d3)piperazine

A prodrug of 4-((1R,3S)-6-chloro-3-phenyl-2,3-dihydro-1H-inden-1-yl)-1,2,2-trimethylpiperazine in the form of 1a or 1b or 4-((1R,3S)-6-chloro-3-(phenyl-d5)-2,3-dihydro-1H-inden-1-yl)-2,2-dimethyl-1-(methyl-d5)piperazine in the form of 2a and 2b

• wherein X− is a counter ion selected from the group consisting of halide anion, optionally fluorinated C1-C10 sulfonate, and optionally fluorinated linear or branched C1-C11 carboxylate;
• and
• wherein R is selected from the group consisting of linear or branched C1-C11 alkyl and C3-C10 cycloalkyl;
• or a pharmaceutically acceptable salt thereof.