Studies of heterocyclic compounds. Part XVI. Mechanism of electrophilic substitution of 6a-thiathiophthens and related compounds: nitrosation with rearrangement
作者:Robert M. Christie、Alexander S. Ingram、David H. Reid、Robert G. Webster
DOI:10.1039/p19740000722
日期:——
6a-thiathiophthens and related compounds occurs with rearrangement. 6a-Thiathiophthens, 1-oxa-6,6a-dithiapentalenes, and 1,6a-dithia-6-azapentalenes rearrange into 1-oxa-6,6a-dithia-2-azapentalenes, and 1,6-dioxa-6a-thiapentalenes into 1,6-dioxa-6a-thia-2-azapentalenes. 6a-Thiathiophthens react with nitrous acid with difficulty unless activated by strongly electron-releasing substituents. 2-t-Butyl-6a-thiathiophthen
6a-硫代噻吩和相关化合物的亚硝化会发生重排。6a-硫噻吩,1-oxa-6,6a-二硫杂戊烯和1,6a-dithia-6-氮杂戊烯重排成1-oxa-6,6a-dithia-2-氮杂戊烯和1,6-dioxa-6a-硫杂戊烯变成1,6-dioxa-6a-thia-2-azapentalenes。除非被强释放电子的取代基激活,否则6a-硫代噻吩难以与亚硝酸反应。2-叔丁基-6a-硫代噻吩在4位反应,以低收率得到3-甲酰基-5-叔丁基-1-氧杂-6,6a-二硫代-2-氮杂戊烯。2-甲硫基5-叔丁基-和2-二甲氨基-5-叔丁基-6a-硫代噻吩在位置3处反应容易,得到3-二硫代羧酸甲酯和3- NN分别将5-叔丁基-1-氧杂-6,6a-二硫-2-氮杂戊烯的-二甲基硫代甲酰胺,对其进行选择性脱硫,得到相应的S-甲基硫代酯和NN-二甲基甲酰胺。5-苯基-,5-叔丁基-和2,5-二甲基-1-氧杂-6,6a-二