Last July, Paul Cooper began working as a doorman at a popular Georgetown nightclub. He made lots of friends and got to know the Georgetown scene. He also made a few buys of cocaine from people he met through his job.

On Thursday night, Cooper threw himself a farewell party at Desperado's, the nightclub where he worked. He was going to get a day job, he told friends. Seven of the invited guests were people who had sold him cocaine.

As the music blared and the liquor flowed, Cooper's real boss, D.C. Police Sgt. Patrick Lanigan, got up on the stage and announced that the party was over. The police were there to arrest some people who had sold cocaine to undercover police officer Paul Cooper.

Six persons, including two other doormen and a waitress at the nightclub at 3350 M St. NW, were arrested and charged with distribution of cocaine. A seventh person was charged with possession of cocaine. An eighth, who did not attend the party, was called at home and told to report to the Second District police station. She also was charged with distribution.

Charges against two of the eight persons were dropped in court yesterday.

Police confiscated between $6,000 and $10,000 worth of cocaine, $2,000 in cash, a 20-gauge shotgun, some marijuana, Quaaludes and amphetamines.

"These are no small-time dealers," said Lanigan. "We had good buys from them."

Lanigan said the arrests Thursday night are part of a long-term investigation of drug dealing in Georgetown. Last Friday, three street vendors and three other persons were arrested on charges that they were part of a ring that sold as estimated $1 million in cocaine to lunchtime and evening crowds in Georgetown and downtown Washington. Three other persons also charged in connection with the operation surrendered to police on Wednesday.

Lanigan said the arrests Thursday were the result of buys that Cooper had arranged in the three months he worked at Desperado's.

Cooper, a rookie who had been on the streets for only two days, was selected by the gambling and vice squad to infiltrate Georgetown clubs where police suspected drugs could be bought.

He went to Desperado's one day in July to apply for a job. He was hired as a doorman. Nightly, he stood at the door, greeting customers and controlling the crowds.

On July 30, he said, he bought one gram of cocaine for $85 from Robert Allen Henry, a doorman at Desperado's. That was his first drug purchase at the nightclub, according to court documents.

In September he purchased $850 worth of cocaine on five separate occasions. Four buys were made inside the club. The fifth was transacted outside the club in a car.

Lanigan said there is no evidence that the management of the club was involved in cocaine sales.

A woman who identified herself as a manager of the nightclub yesterday said, "We believe it was entrapment. They [those arrested] are not drug dealers."

The woman said that because of the arrests, the club closed early Thursday night.

Several plainclothes detectives and four uniformed officers arrived at the club shortly after 10:30 p.m. Thursday. As the guests began filing in, Cooper showed his pleasure that they could make it.

By 11:45 p.m., six persons who had sold him cocaine were inside the club. He gave police in the audience a signal and Lanigan made the announcement. There were about 50 people in the club at the time of the arrests.

Everyone was told to remain seated until after police made the arrests. After the arrests, the other customers cleared out.

Arrested and charged with distribution of cocaine were Jerome Peter Stephens, 30, of 35 Sams Dr., Alexandria; George D. Myers, 27, of 3242 Valley La., Falls Church; Robert Allen Henry, 24, of 6020 Trailside Dr., Silver Spring; Rex Lee Brouillard, 24, of 7903 Birnamwood Dr., McLean; Donald Herbert Farmer, 31, of 12407 Venice Pl., Silver Spring, and Roberta M. Schmitt, 24, of 1454 Beauregard St., Alexandria.

Myers and Henry are doormen at the nightclub and Schmitt works as a waitress. Brouillard is an air cargo logistics expert; Stephens works as a surveyor and Farmer is unemployed, police reported.