Nov 202014


NNC-61-0029, (-) – DRF-2725, NN-622,

(−)DRF 2725

cas   222834-30-2

222834-21-1 (racemate)

Hyperlipidemia; Hypertriglyceridemia; Lipid metabolism disorder; Non-insulin dependent diabetes

PPAR alpha agonist; PPAR gamma agonist


(2S)-2-ethoxy-3-[4-(2-phenoxazin-10-ylethoxy)phenyl]propanoic acid, DRF, 1nyx

Molecular Formula: C25H25NO5
Molecular Weight: 419.4697 g/mol
Dr. Reddy’s Research Foundation (Originator), Novo Nordisk (Licensee)
Antidiabetic Drugs, ENDOCRINE DRUGS, Type 2 Diabetes Mellitus, Agents for, Insulin Sensitizers, PPARalpha Agonists, PPARgamma Agonists
Phase III
EP 1049684; JP 2001519422; WO 9919313
Several related procedures have been described for the synthesis of the title compound. The Horner-Emmons reaction of 4-benzyloxybenzaldehyde (I) with triethyl 2-ethoxyphosphonoacetate (II) afforded the unsaturated ester (IIIa-b) as a mixture of E/Z isomers. Simultaneous double-bond hydrogenation and benzyl group hydrogenolysis in the presence of Pd/C furnished phenol (IV). Alternatively, double-bond reduction by means of magnesium in MeOH was accompanied by transesterification, yielding the saturated methyl ester (V). Further benzyl group hydrogenolysis of (V) over Pd/C gave phenol (VI). The alkylation of phenols (IV) and (VI) with the phenoxazinylethyl mesylate (VII) provided the corresponding ethers (VIII) and (IX), respectively. The racemic carboxylic acid (X) was then obtained by hydrolysis of either ethyl- (VIII) or methyl- (IX) esters under basic conditions.
The synthesis of ragaglitazar (Scheme 1) was commenced by treating substrate 2 under optimized phase-transfer catalyzed conditions, using solid cesium hydroxide monohydrate as the base, a pivalate protected benzyl bromide and the Park and Jew triflurobenzyl-hydrocinchonidinium bromide salt 1. We were delighted to find that this reaction produced 3 in good yield with good selectivity. Subsequent removal of the diphenylmethyl (DPM) group under Lewis acidic conditions followed by a Baeyer-Villager like oxidation yielded the - hydroxy aryl ester 4. At this point, we were again pleased to find that this ester could be recrystalized from warm ether to give essentially enantiomerically pure products (~95% ee). The free hydroxyl was then alkylated using triethyloxonium tetrafluoroborate, and then transesterification under catalytic basic conditions produced 5. A mesylated phenoxazine alcohol reacted with 5 to yield the methyl ester of 6, which was obtained by treatment with sodium hydroxide in methanol. The overall synthesis proceeds with 47% overall yield (41% from commercially available reagents) and is eight linear steps from the alkoxyacetophenone substrate 2, including a recrystalization.


J Med Chem 2001,44(16),2675


Abstract Image

(−)DRF 2725 (6) is a phenoxazine analogue of phenyl propanoic acid. Compound 6 showed interesting dual activation of PPARα and PPARγ. In insulin resistant db/db mice, 6 showed better reduction of plasma glucose and triglyceride levels as compared to rosiglitazone. Compound has also shown good oral bioavailability and impressive pharmacokinetic characteristics. Our study indicates that 6 has great potential as a drug for diabetes and dyslipidemia.


Scheme 1 a


a (a) NaH, DMF, 0−25 °C, 12 h; (b) triethyl 2-ethoxy phosphosphonoacetate, NaH, THF, 0−25 °C, 12 h; (c) Mg/CH3OH, 25 °C, 12 h; (d) 10% aq NaOH, CH3OH, 25 °C, 6 h; (e) (1) pivaloyl chloride, Et3N, DCM, 0 °C, (2) (S)-2-phenyl glycinol/Et3N; (f) 1 M H2SO4, dioxane/water, 90−100 °C, 80 h.

Compound 6 is prepared from phenoxazine using a synthetic route shown in Scheme 1. Phenoxazine upon reaction with p-bromoethoxy benzaldehyde 89 gave benzaldehyde derivative 9. Reacting 9 with triethyl 2-ethoxy phosphonoacetate afforded propenoate 10 as a mixture of geometric isomers. Reduction of 10 using magnesium methanol gave propanoate 11, which on hydrolysis using aqueous sodium hydroxide gave propanoic acid 12 in racemic form. Resolution of 12 using (S)(+)-2-phenyl glycinol followed by hydrolysis using sulfuric acid afforded the propanoic acid 6 in (−) form.

Nate, H.; Matsuki, K.; Tsunashima, A.; Ohtsuka, H.; Sekine, Y. Synthesis of 2-phenylthiazolidine derivatives as cardiotonic agents. II. 2-(phenylpiperazinoalkoxyphenyl)thiazolidine-3-thiocarboxyamides and corresponding carboxamides. Chem. Pharm. Bull198735, 2394−2411

(S)-3-[4-[2-(Phenoxazin-10-yl)ethoxy]phenyl]-2-eth-oxypropanoic Acid (6).  as a white solid, mp: 89−90 °C.

[α]D 25 = − 12.6 (c = 1.0%, CHCl3).

1H NMR (CDCl3, 200 MHz): δ 1.16 (t, J = 7.0 Hz, 3H), 1.42−1.91 (bs, 1H, D2O exchangeable), 2.94−3.15 (m, 2H), 3.40−3.65 (m, 2H), 3.86−4.06 (m, 3H), 4.15 (t, J = 6.6 Hz, 2H), 6.63−6.83 (m, 10H), 7.13 (d, J = 8.5 Hz, 2H). Mass m/z (relative intensity):  419 (M+, 41), 197 (15), 196 (100), 182 (35), 167 (7), 127 (6), 107 (19).

Purity by HPLC: chemical purity: 99.5%; chiral purity: 94.6% (RT 27.5).


EXAMPLE 23 (−) 3-[4-[2-(phenoxazin-10-yl)ethoxy]phenyl]-2-ethoxypropanoic acid:


Figure US06608194-20030819-C00052


The title compound (0.19 g, 54%) was prepared as a white solid from diastereomer [(2S-N(1S)]-3-[4-[2-(phenoxazin-10-yl)ethoxy]phenyl]-2-ethoxy-N-(2-hydroxy-1-phenyl)ethylpropanamide (0.45 g, 0.84 mmol) obtained in example 21by an analogous procedure to that described in example 22. mp: 89-90° C.

[α]D 25=−12.6 (c=1.0% CHCl3)

1H NMR (CDCl3, 200 MHz): δ 1.16 (t, J=7.02 Hz, 3H), 1.42-1.91 (bs, 1H, D2O exchangeable), 2.94-3.15 (complex, 2H), 3.40-3.65 (complex, 2H), 3.86-4.06 (complex, 3H), 4.15 (t, J=6.65 Hz, 2H), 6.63-6.83 (complex, 10H), 7.13 (d, J=8.54 Hz, 2H).


Example 23

(S)-3-[4-[2-(phenoxazin-10-yl)ethoxy]phenyl]-2-ethoxypropanoic acid :


Figure imgf000051_0002

The title compound (0.19 g, 54 %) was prepared as a white solid from diastereomer [(2S- N(lS)]-3-[4-[2-(phenoxazin-10-yl)ethoxy]phenyl]-2-ethoxy-N-(2-hydroxy-l- phenyl)propanamide (0.45 g, 0.84 mmol) obtained in example 21b by an analogous procedure to that described in example 22. mp : 89 – 90 °C. [α]D 25 = – 12.6 (c = 1.0 %, CHC13)

*H NMR (CDC13, 200 MHz) : δ 1.16 (t, J = 7.02 Hz, 3H), 1.42 – 1.91 (bs, IH, D20 exchangeable), 2.94 – 3.15 (complex, 2H), 3.40 – 3.65 (complex, 2H), 3.86 – 4.06 (complex, 3H), 4.15 (t, J = 6.65 Hz, 2H), 6.63 – 6.83 (complex, 10H), 7.13 (d, J = 8.54 Hz, 2H).

Patent Submitted Granted
Benzamides as ppar modulators [US2006160894] 2006-07-20
Novel tricyclic compounds and their use in medicine process for their preparation and pharmaceutical compositions containing them [US2002077320] 2002-06-20
Tricyclic compounds and their use in medicine process for their preparation and pharmaceutical compositions containing them [US7119198] 2006-07-06 2006-10-10
Tricyclic compounds and their use in medicine: process for their preparation and pharmaceutical compositions containing them [US6440961] 2002-08-27
Tricyclic compounds and their use in medicine process for their preparation and pharmaceutical compositions containing them [US6548666] 2003-04-15
Tricyclic compounds and their use in medicine process for their preparation and pharmaceutical compositions containing them [US6608194] 2003-08-19
Pharmaceutically acceptable salts of phenoxazine and phenothiazine compounds [US6897199] 2002-11-14 2005-05-24
Tricyclic compounds and their use in medicine process for their preparation and pharmaceutical compositions containing them [US6939988] 2005-09-06


  1. wo/2014/181362 a process for the preparation of 3 … – WIPO


A process for the preparation of 3-aryl-2-hydroxy propanoic acid compounds

ragaglitazar; saroglitazar

Council of Scientific and Industrial Research (India)

Process for preparing enantiomerically pure 3-aryl-2-hydroxy propanoic acid derivatives (eg ethyl-(S)-2-ethoxy-3-(4-hydroxyphenyl)propanoate), using S-benzyl glycidyl ether as a starting material. Useful as intermediates in the synthesis of peroxisome proliferator activated receptor agonist such as glitazars (eg ragaglitazar or saroglitazar). Appears to be the first filing on these derivatives by the inventors; however see WO2014181359 (for a concurrently published filing) and US8748660 (for a prior filing), claiming synthesis of enantiomerically pure compounds.

  1. Dolling, U. H.; Davis, P.; Grabowski, E. J. J. Efficient Catalytic Asymmetric Alkylations. 1. Enantioselective Synthesis of (+)-Indacrinone via Chiral Phase-Transfer Catalysis. J. Am. Chem. Soc. 1984, 106, 446–447.
  2. Andrus, M. B.; Hicken, E. J.; Stephens, J. C. Phase-Transfer Catalyzed Asymmetric Glycolate Alkylation. Org. Lett. 2004, 6, 2289–2292.
  3. Andrus, M. B.; Hicken, E. J.; Stephens, J. C.; Bedke, D. K. Asymmetric Phase-Transfer Catalyzed Glycolate Alkylation, Investigation of the Scope, and Application to the Synthesis of (-)-Ragaglitazar. J. Org. Chem. 2005, ASAP.
  4. Henke, B. R. Peroxisome Proliferator-Activated Receptor  Dual Agonists for the Treatment of Type 2 Diabetes. J. Med. Chem. 2004, 47, 4118–4127.
  5. Wilson, T. M.; Brown, P. J.; Sternbach, D. D.; Henke, B. R. The PPARs: from orphan receptors to drug discovery. J. Med. Chem. 2000, 46, 1306–1317.
  6. Uchida, R.; Shiomi, K.; Inokoshi, J.; Masuma, R.; Kawakubo, T.; Tanaka, H.; Iwai, Y.; Omura, A. Kurasoins A and B, New Protein Farnesyltrasferase Inhibitors Produced by Paecilomyces sp. FO-3684. J. Antibio. 1996, 49, 932–934.

Sorry, the comment form is closed at this time.


Get every new post on this blog delivered to your Inbox.

Join other followers: