Indacrinone Explained

Iupac Name:[(6,7-Dichloro-2-methyl-1-oxo-2-phenyl-2,3-dihydro-1''H''-inden-5-yl)oxy]acetic acid
Cas Number:56049-88-8
Unii:B926Y9U4QN
Chemspiderid:38545
Pubchem:42266
C:18
H:14
Cl:2
O:4
Smiles:CC1(Cc2cc(c(c(c2C1=O)Cl)Cl)OCC(=O)O)c3ccccc3
Stdinchi:1S/C18H14Cl2O4/c1-18(11-5-3-2-4-6-11)8-10-7-12(24-9-13(21)22)15(19)16(20)14(10)17(18)23/h2-7H,8-9H2,1H3,(H,21,22)
Stdinchikey:PRKWVSHZYDOZLP-UHFFFAOYSA-N

Indacrinone is a loop diuretic. It can be used in patients of gout with hypertension as an antihypertensive because it decreases reabsorption of uric acid,[1] while other diuretics increase it.

Chirality and biological activity

Indacrinone is a chiral drug, with one chiral center and hence exists as mirror-image twins. (R)-enantiomer, the eutomer, is diuretic whereas the mirror-image version (S)-enantiomer counteracts side effect of the eutomer. Here both the enantiomers contribute to the overall desired effect in different ways.

As indicated earlier, the (R)- enantiomer is the pharmacologically active diuretic. Like most other diuretics, the (R)-isomer possesses an undesirable side-effect of retaining uric acid. But the (S)-enantiomer, the distomer, has the property of assisting uric acid secretion (uricosuric effect), and, therefore, antagonizing the undesirable side-effects of the eutomer (uric-acid retention).[2] [3] It affords a good argument for the marketing of a racemic mixture. But studies exemplify that 9:1 mixture of the two enantiomers provides optimal therapeutic value.[4]

Synthesis

The Friedel-Crafts acylation of 2,3-dichloroanisole [1984-59-4] (1) with phenylacetyl chloride [103-80-0] (2) gives 2,3-dichloro-4-phenylacetylanisole [59043-83-3] (3). A variation of the Mannich reaction is performed employing tetramethyldiaminomethane [51-80-9] (this is an aminal of dimethylamine and formaldehyde). The intermediate reaction product (5), which is not isolated, would undergo a β-Hydride elimination with concomitant loss of dimethylamine and formation of the corresponding enone, 2,3-Dichloro-4-(2-phenylacryloyl)anisole (PC10924810) (6). Acid catalyzed (H2SO4) intramolecular cyclization gives the indanone (PC10990444) (7). This is O-demethylated under acidic conditions to give 2-Phenyl-5-hydroxy-6,7-dichloro-1-indanone, PC12774089 (8). The phenol thus obtained is then alkylated on oxygen by iodoacetic acid [64-69-7] (9) affording PC20520826 (10). Alkylation with iodomethane [74-88-4] in the presence of sodium hydride completed the synthesis of indacrinone (11).

See also

Notes and References

  1. Vlasses PH, Rotmensch HH, Swanson BN, Irvin JD, Johnson CL, Ferguson RK . Indacrinone: natriuretic and uricosuric effects of various ratios of its enantiomers in healthy men . Pharmacotherapy . 4 . 5 . 272–7 . 1984 . 6504708 . 10.1002/j.1875-9114.1984.tb03374.x . 19743065 .
  2. Ariëns . Everardus J. . 1986 . Stereochemistry: A source of problems in medicinal chemistry . Medicinal Research Reviews . 6 . 4 . 451–466 . 10.1002/med.2610060404 . 3534485 . 36115871 . 0198-6325.
  3. Web site: Kannappan . Valliappan . Indacrinone – Chiralpedia . 2022-08-28 . en-US.
  4. Book: The impact of stereochemistry on drug development and use . 1997 . Wiley . Hassan Y. Aboul-Enein, Irving W. Wainer . 0-471-59644-2 . New York . 35262289.