On the synthesis of novel spiroglucosides and fused ring heterocycles from diethyl <img src='/image/spc_char/alpha.gif' border=0>-acetamido-<img src='/image/spc_char/alpha.gif' border=0>-bromomalonate

932-937Diethyl -acetamido--bromomalonate 1 with thiocarbamides 2 and 4-substituted thiosemicarbazides 8 give 2-alkyllarylimino-5-amino-5-carbethoxy-4-oxo-(3H)-thiazoles <b style="mso-bidi-font-weight: normal">3 and 2-alkyllarylimino-6-amino-6-carbethoxy-5-oxo-(3H, 4H)-1,3,4-thiadiazines 9 respectively. Compounds 3 and <b style="mso-bidi-font-weight: normal">9 with arylisothiocyanate 4 afford spiro [4.4]nonane and spiro[5.4]decane derivatives. These spiroheterocycles on reaction with 2,3,4,6-tetrabenzoyl--D-glucopyranosyl bromide 6 give novel spiroglucosides. Also compounds 3 and 9 with hydrazine hydrate give fused pyrazolo[5,4-d]thiazole and pyrazolo[5,4-e]thiadiazine derivatives respectively. The characterisation of the products has been done on the basis of spectral (IR, 1H NMR, and 13C NMR) data

Design and synthesis of new spiroheterocycles: Selective role of potassium fluoride in DMF

1041-1047Potassium fluoride (KF) in dimethyl formamide (DMF) is found to be very effec tive and selec tive in the synthes is of spiro compounds. 4-Bromo-4-carbethoxy-(4H)-1-phenyl-3-substitutedpyrazol-5-ones 4 are selectively converted to spiro derivatives by reacting with 5,8,11 and 16

Synthesis of 4-carbethoxy-4<i>H</i>-3-substitutedisoxazol-5-ones and their conversion into novel spiroheterocycles

68-70Interaction of diethyl α-acyl/aroylmalonates 1 with hydroxylamine hydrochloride 2 afford 4-carbethoxy-4H-3-substituted isoxazol-5-ones 3 and 3-substitu ted-4H-5-oxo-isoxazol-4- carboxylic acids 4. Bromination of 3 affords 4-bromo derivatives 5, which with thiocarbamides. 4-substituted thiosemicarbazides give 2-alkyl/arylimino-4, 9-dioxo-3, 7-diaza-8-oxa-6-substituted-1-thia-(3H)-spiro[4,4]nonan-6,enes 7 and 2-alkyl/arylimino-5, 10-diox(l-9-oxa-7-substituted-l-thia-3, 4, 8-triaza-(3H, 4H)- spiro[5,4]dec-7-enes 8. Characterisation of the products has been done on the basis of spectral (IR,1H NMR and 13C NMR) data