Why did the high priests try Jesus on charges of Blasphemy if He fulfilled their prophecy?

The high priests didn't care about the scriptures. The high priests at that time were agents of Rome.

It was standard procedure for the Romans, after conquering a nation, to depose the nation's leaders (both political and religious) and replace them with people who would be loyal to Rome.

In the case of Judea, that meant replacing the Hasmonean king with Herod, and replacing the Levitical high priest with Annas ben Seth. (This is the same Annas mentioned in the gospels as being high priest along Caiaphas. Technically, Annas had been appointed by Quirinius--the same Quirinius of the famous census--and deposed by Valerius Gratus, Pilate's immediate predecessor. However, Annas was succeeded first by his son Eleazar and then by his son-in-law Caiaphas, and following Caiaphas, by four more of Annas' sons.) During the years of Roman rule, Annas and his family held the title of high priest for more than half a century. Caiaphas himself managed to hold the office for 18 years, including Pilate's entire term as governor.

In other words, this was a family that had earned the Romans' trust, and they were rewarded for it.

That's why, when Jesus showed up with followers proclaiming him to be the Messiah, the high priests saw him as a threat. As Jeff Wolski points out in his answer, most Jews at the time expected the Messiah to free them from Roman rule. This would have meant a return of the high priesthood to the Levites, and a loss of power for the family of Annas. And that's why they wanted him dead.

“If we let him go on like this, everyone will believe in him, and the Romans will come and destroy both our holy place and our nation.” But one of them, Caiaphas, who was high priest that year, said to them, “You know nothing at all! You do not understand that it is better for you to have one man die for the people than to have the whole nation destroyed.” He did not say this on his own, but being high priest that year he prophesied that Jesus was about to die for the nation, and not for the nation only, but to gather into one the dispersed children of God. (John 11:48-52)

Caiaphas thought that Jesus' death would appease Roman leaders who perceived Jews as unruly, ungrateful subjects. He didn't even realize his words would have a deeper meaning.

To be sure, the Jewish leaders should have accepted Jesus. The miraculous signs He performed was irrefutable evidence that He had come from God, as Nicodemus, himself a Pharisee, noted.

Now there was a man of the Pharisees, named Nicodemus, a ruler of the Jews; 2 this man came to Jesus by night and said to Him, “Rabbi, we know that You have come from God as a teacher; for no one can do these signs that You do unless God is with him.” John 3:1-2 NASB

However, God has prophesied this through Isaiah the prophet, as John notes later.

But though He had performed so many signs before them, yet they were not believing in Him. 38 This was to fulfill the word of Isaiah the prophet which he spoke: “Lord, who has believed our report? And to whom has the arm of the Lord been revealed?” 39 For this reason they could not believe, for Isaiah said again, 40 “He has blinded their eyes and He hardened their heart, so that they would not see with their eyes and perceive with their heart, and be converted and I heal them.” 41 These things Isaiah said because he saw His glory, and he spoke of Him. John 12:37-41 NASB

However, many of the rulers, including Nicodemus and Joseph of Arimathea, did, in fact, believe in Jesus and accept Him as their Messiah. Yet, the Pharisees as a group were imposing significant consequences on anyone who followed Jesus, so there was a lot of fear that led to many believing in secret. Sadly, it seems, at least prior to Jesus' death and resurrection, that they loved the approval of men more than the approval of God.

Nevertheless many even of the rulers believed in Him, but because of the Pharisees they were not confessing Him, for fear that they would be put out of the synagogue; 43 for they loved the approval of men rather than the approval of God. John 12:42 NASB

The account is detailed in Matthew 26 starting verse 57.

First, the Sanhedrin attempted to convict Jesus on false pretenses, but that failed. Then this was said:

62 Then the high priest stood up and said to Jesus, “Are you not going to answer? What is this testimony that these men are bringing against you?” 63 But Jesus remained silent.

The high priest said to him, “I charge you under oath by the living God: Tell us if you are the Messiah, the Son of God.”

64 “You have said so,” Jesus replied. “But I say to all of you: From now on you will see the Son of Man sitting at the right hand of the Mighty One and coming on the clouds of heaven.”[e]

65 Then the high priest tore his clothes and said, “He has spoken blasphemy! Why do we need any more witnesses? Look, now you have heard the blasphemy. 66 What do you think?”

“He is worthy of death,” they answered.

In verse 64, Jesus basically calls himself God. That is blasphemy.

Any prophecies that Jesus might have fulfilled was apparently irrelevant to the Sanhedrin. Continuously in the Gospels, they attempt to trap Jesus, trick Him into sin that warranted arrest, and they even went to stone Him for blasphemy earlier (See John 10:22). They just plain didn't like Him, mostly because He did not fit in the box they wanted the Messiah to fit in, which was more of a conqueror that would bring Israel back to its glory days of King Solomon. They also did not expect the Messiah to claim to be God. Further, Jesus continuously aggravated the Sanhedrin by making them look like fools and hypocrites.