2338-18-3

The invention discloses a preparation method of a 2-aminoindan derivative. The preparation method comprises the following steps: with a 1-indanone derivative as a starting raw material, carrying out oximation reaction, and synchronously reducing carbonyl and hydroxyl oxime under the catalysis of Lewis acid such as aluminum chloride in the presence of a boron metal reducing agent, so as to obtain the 2-aminoindan derivative. The invention further provides the 2-aminoindan derivative prepared by virtue of a synthetic method and a corresponding intermediate derivative. Compared with a synthetic method of the 2-aminoindan derivative in the prior art, the synthetic method disclosed by the invention has the beneficial effects that (1) only two reaction steps are adopted, and the reaction steps are obviously less than the reaction steps in the prior art; (2) the cost is relatively low, the operation is simple and convenient, and the yield is high; and (3) the preparation method is suitable for large-scale industrial production and has relatively good application prospects.

The direct partial reduction of highly stable secondary amides to more reactive aldimines and aldehydes is a challenging yet highly demanding transformation. In this context, only three methods have been reported. We report herein an improved version of the Charette’s method. Our protocol consists of activation of secondary amides with triflic anhydride/2-fluoropyridine, and partial reduction of the resulting intermediates with 1,1,3,3-tetramethyldisiloxane (TMDS), which delivered aldimines or aldehydes upon acidic hydrolysis. Aromatic amides were reduced to the corresponding aldimines in 85%–100% NMR yields, and yields (NMR) from aliphatic amides were 72%–86%. Acidic hydrolysis of the aldimine intermediates afforded, in one-pot, the corresponding aldehydes in 80%–96% yields. A simple protocol was established to isolate labile aldimines in pure form in 92%–96% yields. The improved method gave generally higher yields as compared to the known ones, and features the use of cheaper and more atom-economical TMDS as a chemoselective reducing agent. In addition, a convenient extraction protocol has been established to allow the isolation of amines, which constitutes a mild method for the N-deacylation of amides, another highly desirable transformation. The extended method retains the advantages of the original method of Charette in terms of mild conditions, good functional group tolerance, and excellent chemoselectivity.

2-Amino-5,6-dimethoxyindan hydrochloride was synthesized in seven steps and with an overall yield of 48%. Indan-2-ol was converted to 5,6-dibromo-indan-2- ol in three steps by acetylation, electrophilic bromination and deacetylation. Dimethoxylation of 5,6-dibromoindan-2-ol with NaOCH3 in the presence of CuI gave 5,6-dimethoxy-indan-2-ol, which was converted to 2-amino-5,6-dimethoxyindan hydrochloride by azidation, followed by Pd-C catalyzed hydrogenation. Similarly, 2-amino-5-bromoindan was synthesized in five steps and with an overall yield of 50%. Indan-2-ol was converted to 2-aminoindan by azidation followed by Pd-C catalyzed hydrogenation. The reaction of 2-aminoindan with 2.5 equiv Br2 afforded 2-amino-5,6- dibromoindan.

The need for an economical process for producing 2-aminoindan hydrochloride, a key starting material in manufacturing novel bioactive molecules, motivated development of a novel synthetic route using an inexpensive reactant, ninhydrin. The synthesis, involving oximation of ninhydrin followed by catalytic reduction of the resulting oxime intermediate to give 2-aminoindan, was demonstrated successfully, and a product purification scheme was developed to isolate 2-aminoindan as the hydrochloride salt form. Subsequent process development optimized the reduction step by identifying regimes of fast and slow reaction (corresponding to reduction of oxime and diketone functions, respectively), and tailoring reaction conditions to use mild conditions during the fast exothermic regime to ensure process safety followed by more severe conditions for the slower reaction. The process was successfully scaled up 100-fold in a pilot plant, with excellent yield and product quality agreement between laboratory and pilot plant.

Compounds of the formula I wherein R2—C, R3—C, R4—C or R5—C may be replaced by N; and wherein n is 1, 2 or 3; R1is aryl, cycloalkyl or heterocyclyl; R2, R3, R4and R5are independently hydrogen, optionally substituted alkyl, halo, amino, substituted amino, trifluoromethyl, cyano, carboxyl, alkoxycarbonyl, aralkoxycarbonyl, (alkyl, aryl or aralkyl)-thio, (alkyl, aryl or aralkyl)-oxy, acyloxy, (alkyl, aryl or aralkyl)-aminocarbonyloxy; or any two of R2, R3, R4and R5at adjacent positions are alkylenedioxy; R6is hydrogen, optionally substituted alkyl, amino, substituted amino, acylamino, wherein Rais hydrogen or optionally substituted alkyl, Rband Rcare independently hydrogen, optionally substituted alkyl, cycloalkyl, aryl or heterocyclyl; or Rband Rctogether represent lower alkylene or lower alkylene interrupted by O, S, or N—(H, alkyl or aralkyl); Rdis optionally substituted alkyl, cycloalkyl, aryl or heterocyclyl; and Reis optionally substituted alkyl, aryl, heterocyclyl, cycloalkyl, amino or substituted amino; and pharmaceutically acceptable salts thereof; and enantiomers thereof; which are useful as inhibitors of microsomal triglyceride transfer protein (MTP) and of apolipoprotein B (ApoB) secretion.

Three series of bicyclic, semirigid congeners of β-phenethylamine have been prepared for evaluation of the effect of ring size (and of concomitant conformational variation) on biological activity in a variety of assays for adrenergic and dopaminergic actions.Pharmacologic activity was associated with 2-aminotetralin and 2-aminoindan derivatives, but was not found with 6-aminobenzocycloheptene derivatives.Noteworthy is the ability of several aminotetralins and aminoindans to increase the hot-plate reaction time without eliciting dopaminergic effects.This action was not blocked by pretreatment with naloxone.