Condensed Diazepines. Synthesis of 1-R-3,4-Dihydro-5 H -Benzothieno[2,3- d ][1,2]Diazepin-4-Ones
- PDF / 458,897 Bytes
- 11 Pages / 595.276 x 793.701 pts Page_size
- 103 Downloads / 150 Views
CONDENSED DIAZEPINES. SYNTHESIS OF 1-R-3,4-DIHYDRO5H-BENZOTHIENO[2,3-d][1,2]DIAZEPIN-4-ONES V. S. Tolkunov1*, A. B. Eres'ko1, A. V. Mazepa2, G. V. Palamarchuk3, O. V. Shishkin3,4, and S. V. Tolkunov1 Novel 1-R-3,4-dihydro-5H-benzothieno[2,3-d][1,2]diazepin-4-ones have been prepared by the cyclization of 2-acyl(aroyl)benzo[b]thiophene-3-acetic acids or 1-R-benzothieno[2,3-c]pyr-3-ones with hydrazine hydrate. Keywords: 2-acyl(aroyl)benzo[b]thiophene-3-acetic acids, 1-aryl-3,4-dihydro-5H-benzothieno[2,3-d][1,2]diazepin-4-ones, hydrazine hydrate, cyclization. 1-Aryl-3,5-dihydro-4H-2,3-benzodiazepin-4-ones are actively studied in connection with their antispasmodic activity [1-4]. They are also of interest as starting materials in the synthesis of condensed triazoloand tetrazolo-2,3-benzodiazepines [5-9]. Known routes for preparing 2,3-benzodiazepin-4-ones are based on the reaction of hydrazine with 2-aroyl(acetyl)-4,5-dimethoxyphenylacetic acids or their esters [10, 11]. Amongst heterocyclic analogs of 2,3-benzodiazepin-4-ones there are known only 3H-[1,2]diazepino[5,6-b]indoles and the 2,3-dihydro-2-oxo1H-[1,2]diazepino[4,5-b]indoles and 1-aryl-3,4-dihydro-5H-benzofuro[2,3-d][1,2]diazepin-4-ones obtained by us [12-14]. In continuing our work on the synthesis of hetero analogs of 2,3-benzodiazepin-4-ones, we have studied the cyclization of 2-acyl(aroyl)benzo[b]thiophene-3-acetic acids, their methyl esters, and amides using hydrazine hydrate. Under the same experimental conditions the reaction occurs differently for the 2-acetyl- (1a) and 2-propionyl-5-methylbenzo[b]thiophene-3-acetic acid (1b) with hydrazine hydrate in alcohol or the sodium salts of these acids in water with subsequent acidification by acetic acid. Acid 1a gives the hydrazone 2, while the reaction of acid 1b with hydrazine leads to the azine 3. Moreover, heating hydrazone 2 in acetic acid does not _______ *To whom correspondence should be addressed, e-mail: [email protected]. 1
L. M. Litvinenko Institute of Physico Organic Chemistry and Coal Chemistry, Ukraine National Academy of Sciences, 70 R. Luxemburg St., Donetsk 83114, Ukraine. 2 A. V. Bogatsky Physico-Chemical Institute, Ukraine National Academy of Sciences, 86 Lyustdorfskaya Road, Odessa 65080, Ukraine; e-mail: [email protected]. 3 Scientific-Technological Complex "Institute of Monocrystals", Ukraine National Academy of Sciences, 60 Lenin Ave., Kharkiv 61001, Ukraine; e-mail: [email protected]. 4 V. N. Karazin National University, 4 Freedom Sq., Kharkiv 61077, Ukraine; e-mail: [email protected]. _________________________________________________________________________________________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1471-1482, September, 2012. Original article submitted January 6, 2012. 0009-3122/12/4809-1371©2012 Springer Science+Business Media New York
1371
give the corresponding azine (as observed for benzo[b]furan and indole hydrazones having a similar structure [13, 15]). In the presence of dicyclohexylcarbodiimide (DCC),
Data Loading...
