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N<br />

N<br />

Br<br />

R 2<br />

N<br />

N<br />

3<br />

N<br />

H<br />

N<br />

OH<br />

R1 N 3<br />

n<br />

MeCN, 75 o C,<br />

3 Hrs<br />

N<br />

n 3<br />

+<br />

R 2<br />

1 2<br />

Br<br />

O<br />

R 1<br />

One Pot MW ?<br />

o MW. 100 C<br />

MeCN, 10 min<br />

N2H4 (7 equiv)<br />

Scheme-1 Sequential Synthesis of 2-AI-T Framework<br />

R 2<br />

R 1<br />

R 2<br />

R 1<br />

N<br />

N<br />

H<br />

H<br />

N<br />

N<br />

NH<br />

N<br />

N R3 N<br />

n<br />

MW. 100 o C<br />

Cu(OAc) 2<br />

10 min, 80 %<br />

In continuation of earlier work on two step synthesis of 2-AI-T scaffold with excellent<br />

yield. now an ameliorated and convenient one-pot protocol for the synthesis of 2-AI-T<br />

scaffold under microwave conditions has been reported.<br />

4.2 Optimization Study<br />

Looking to the current exploration in the synthesis and microwave-assisted decoration<br />

of the 2-aminoimidazole 14 and click reaction 15 and preliminary success of the<br />

sequence, it was very interesting to investigate whether one-pot protocol for the<br />

construction of 2-AI-T scaffold should be possible. The test reaction was performed<br />

with hydroxy salt {3} and phenyl acetylene as a model system. Different Cu catalyst,<br />

equiv of NH2NH2.H2O, temperature and reaction time were screened to derive an<br />

optimized protocol (Table 1).<br />

First, the application of Cu(OAc)2 as catalyst for click reaction and different<br />

equivalents of aqueous NH2NH2.H2O for simultaneous dimorth rearrangement (Table-<br />

1, No-1-3) was evaluated. However in case of 1 equiv. of hydrazine used, yield was<br />

only 51 %. (Table-1, No-1). Next study of different reaction time (Table-1, No-3-7)<br />

performed. It was observed that reaction could complete even in very short time<br />

4<br />

NH<br />

5<br />

R 3<br />

N 3<br />

n

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