Thiazolo azepines

Abweichend von den o.g. Reaktionen der l,3-Thiazolium-3-methide mit Alkenen bilden sich mit Alkinen 1,3-Thiazolo-azepine als 1 2-Cycloaddukte985. 

Solvent has an important influence on the course of this cycloaddition, and in the reaction of 2,5-dimethylthiazole with DMAD in DMF the product analogous to (415) was obtained. However, in DMSO or acetonitrile a thiazolo[3,2-a]azepine was formed in addition to this product, whereas with THF, dichloromethane or nitromethane, only the thiazoloazepine was isolated. 

Attempts to extend this reaction to the expansion of 6-azidoindoles and 6-azidobenzimidazoles failed.147 However, 6-azidobenzothiazoles 4 in diethylamine solution, or in potassium methox-ide-methanol/dioxane mixture (see Section 3.2.1.4.2.1.), furnish 8/7-thiazolo[5,4-c]azepines 5, albeit in poor to moderate yields. In amine solution,, V6,A6-diethylbenzothiazole-6,7-diamines are the major products.147... 

In order to study the behavioural effects in rats of the dopamine agonist 2-amino-6-allyl-5,6,7,8-tetrahydro-4//-thiazolo[4,5-Boehringer Ingelheim, BHT for short) a recording device, the holeboard (.Figure 6.1) with infrared photobeams covering an open field was used [2]. The apparatus allows ten different measurements (which will be labelled x, - x,0) of behaviour to be recorded simultaneously. The rats (n = 23)... 

Key BRL37344 = Sodium-4-(2-[2-hydroxy- 3-chlorophenyl ethylamino]propyl)phenoxyacetate BHT920 = 6-Allyl-2-amino-5,6,7,8-tetrahydro-4//-thiazolo-[4,5-<7]-azepine... 

Substituted benzothiazoles 201 (R = NH2) were rearranged to thiazolo[5,4-c]azepin-8-one 615 under the conditions of Schmidt reaction. 

Many photoreactions of aryl azides can be interpreted as arising via unstable ring-fused azirines. The formation of the 6,7-diaminobenzothiazoles (117) and the 6-amino-8//-thiazolo[5,4-c]azepines (118) on irradiation of the corresponding 6-azidobenzothiazoles (119) in diethylamine can be explained in this way, as shown in Scheme 14. An alternative explanation for the photodecomposition of phenyl azide (120) at low temperatures has recently been advanced and involves the formation of an intermediate l-azacyclohepta-l,2,4,6-tetraene (121). Further evidence for this pathway is to be found in a study of the photodecomposition of phenyl azide in acetic acid the azepin-2-one (122) is believed to arise in this way, as shown in Scheme 15. The formation of the same azepin-2-one on irradiation of phenyl azide in the presence of naked acetate anion has been reported the nature of the intermediate in this transformation is still open to question, but both benzazirine and l-azacyclohepta-l,2,4,6-tetraene intermediates are considered possible. In contrast, irradiation of the azide (123) in an argon matrix at lOK affords, on the basis of spectral evidence, the cyclic carbodi-imide (124). " 2-... 

Thiazolo[3.2-a]azepines[C NS-CgN]. Cyclisation of (272), followed by hydrazine deprotection gave (273) which was reacted at exo N3[Pg.189]

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