Spirocyclopropane compounds. VI Synthesis of spiro(benzo(b)thiophene-2(3H),1'-cyclopropan)-3-ones.
作者:MITSURU KAWADA、HIROSADA SUHIHARA、ISUKE IMADA
DOI:10.1248/cpb.34.1939
日期:——
Spiro[benzo[b]thiophene-2(3H), 1'-cyclopropan]-3-ones (IIIc-1-IIIc-11) and their aza analogs, such as spiro[cyclopropane-1, 2'(3'H)-thieno[3, 2-c]pyridin]-3'-one (IIIc-12) as well as spiro[cyclopropane-1, 2'(3'H)-thieno[2, 3-b]pyridin]-3'-one (IIIc-13), were synthesized from thiosalicylic acids and from 4- and 2-mercaptonicotinic acids, respectiely, in three steps. Decarboxylation of 4', 5'-dihydrospiro[benzo[b]thiophene-2(3H), 3'(2'H)-furan]-2', 3-diones (IIc) gave 2, 3-dihydrobenzo[b]thieno[3, 2-b]furans (IVc) along with the desired spirocyclopropane compounds (IIIc).The ratios of IIIc to IVc were greatly influenced by the substituents on the benzene ring.
Spiro[苯并[b]噻吩-2(3H), 1'-环丙烷]-3-酮 (IIIc-1-IIIc-11) 及其氮杂类,如spiro[环丙烷-1, 2'(3'H)-噻吩[3, 2-c]吡啶]-3'-酮 (IIIc-12) 和spiro[环丙烷-1, 2'(3'H)-噻吩[2, 3-b]吡啶]-3'-酮 (IIIc-13),分别由硫水杨酸和4-、2-巯基烟酸经过三步反应合成。4', 5'-二氢spiro[苯并[b]噻吩-2(3H), 3'(2'H)-呋喃]-2', 3'-二酮 (IIc) 的脱羧反应产生了2, 3-二氢苯并[b]噻吩[3, 2-b]呋喃 (IVc) 以及所需的spiro环丙烷化合物 (IIIc)。IIIc与IVc的比例受到苯环上取代基的显著影响。