Novel regioselective formation of S- and N-hydroxyl-alkyls of 5-(3-chlorobenzo[b]thien-2-yl)-3-mercapto-4H-1,2,4-triazole and a facile synthesis of triazolo-thiazoles and thiazolo-triazoles. Role of catalyst and microwave.
Regioselective alkylation of 5-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole (1) with hydroxy alkylating agents 2, 3, 13, and the 2,3-O-isopropylidene-1-O-(p-tolylsulfonyl)-glycerol (10) afforded the corresponding S-alkylated derivatives 6, 7, 11, and 14 under both conventional and microwave irradiation conditions; bentonite as a solid support gave better results, with no change in regioselectivity. A facile intramolecular dehydrative ring closure of 6, 7, 11, and 14 using K(2)CO(3) in DMF afforded the corresponding fused triazolo-thiazines and thiazolo-triazole 17-19. The isopropylidenes and acetyl derivatives of the products were prepared.
Ashry
E S H El
ES
Chemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt. eelashry@hotmail.com
Kassem
A A
AA
Abdel-Hamid
H
H
Louis
F F
FF
Khattab
Sh A N
ShA
Aouad
M R
MR
D000478:Alkylation / Q000528:radiation effects; D002384:Catalysis / Q000528:radiation effects; D000431:Ethanol / Q000031:analogs & derivatives / Q000737:chemistry; D008872:Microwaves; D019346:Sodium Acetate / Q000737:chemistry; D013237:Stereoisomerism; D013843:Thiazines / Q000737:chemistry; D013844:Thiazoles / Q000737:chemistry*; D014230:Triazoles / Q000138:chemical synthesis / Q000737:chemistry*
D013843:Thiazines; D013844:Thiazoles; D014230:Triazoles; C098088:sodium ethoxide; D000431:Ethanol; D019346:Sodium Acetate