Download (8Mb) - Etheses - Saurashtra University

10
11
Cl
Cl
N
N
H
N
H
N
N
N
Cl 4-j (85)
N
N
H
N
H
N
N
N
Cl 4-k (80)
21
22
Cl
Cl
N
N
H
N
N
H
NH
N H
N N
N
N
N
N
S
4-u (91)
Br 4-v (80)
a
All reactions were run on a 0.7 mmol scale of 3 {a-j} ethanol: water (4:1) (1 ml) with
phenyl acetylene (1.2 equiv), Cu(OAc)2 (5 mol % ) and hydrazine hydride (2 equiv).
The mixture was irradiated in a sealed tube (CEM Discover @ ) at a ceiling temperature
of 100 o C and 35 maximum power for the stipulated time. b isolated yields. Yields are
shown in ().
Table-2: Microwave assisted one pot decoration of 2-AI-T Framework a .
A diverse set of 2-AI-T scaffold were synthesized with these optimized conditions.
Ten different hydroxy salt 3 {a-j} (n = 1 or 2) were reacted with different (hetero)
aromatic or alkyl acetylenes (Table-2) to test the generality of this new microwaveassisted
one pot method (Table 2). All reactions were completed within 5 min using
microwave irradiation at ceiling temperature of 100 o C and 35W power. The yields
varied from good to excellent, although in some cases lower yields were observed
(Table 2, No-15,16 and 19). However in case of morpholine substitution (table-2, No-
15-16) probably due to decomposition of starting hydroxy salt 3 {h} lower yields
were observed. Interestingly when 4,5-disubstituted hydroxy salt react with acetylene
only 16% of desired product 4{s} was observed due to steric hindrance of 4-Mephenyl
substitution on dimorth rearrangement. Motivated by the importance of the
final target to develop new general method toward widely functionalized 2-AI-T
framework, we next examined the extension of this procedure to other acetylene. The
reaction proceeded effectively with aliphatic and aromatic terminal acetylenes to give
the corresponding 2-AI-T (Table 2). Thus, a variety of substituted 2-AI-T containing
aromatic, aliphatic, cyclic and heterocyclic substitution at the C-4 position of the
triazole ring were obtained.