The battle for the Kenesaw apartment building had been raging for almost two years when last week, the tenants finally appeared to be winning.

A large but badly deteriorated building at 16th and Irving streets NW, it is a central point in the confrontation between the current residents of the Adams-Morgan and Mount Pleasant areas, and the land developers who have been seeking properties there. "The Georgetownization of Adams-Morgan," one Kenesaw resident derisively called the trend, which has forced land prices and rents so high that many people have been forced to move out of the neighborhoods.

When Antioch University of Yellow Springs, Ohio, and its law school here decided to sell the property for $750,000 in early 1977 because the building - a gift - was losing so much money. The tenants there began their struggle to buy it and keep it.

The nearly 30 families in the Kenesaw, many of them immigrants from Latin America with very small incomes, staved off the bids of private developers, organized, protected, held fund raisers, obtained deadline extensions, and finally, last week, with the help of the District of Columbia Development Corporation (DCDC) and Perpetual Federal Savings and Loan, were in a position to give Antioch the $750,000 it wanted.

Then suddenly, in a move that stunned the tenants, a mystereious corporation in Providence, R.L., offered the university $900,000 cash for the property, and Antioch appears likely to accept it.

"Everything was quiet until last week," said DCDC vice president Brady Armstrong, who has worked closely with the Kenesaw cooperative. "Then we received a barrage of paper - commitments from financial institutions for rehabilitation and acquisition. All of a sudden we were in great spirits. But then the same day Antioch got his bid from another buyer."

The other buyer was something called the NEMAC Development Corporation, a business entity chartered in Rhode Island on May 23, the same day that it offered $825,000 to Antioch and deposited $20,000 in an escrow account.

Under a deadline extension agreement, made in March, Anthioch could accept other bids made, DCDC had three working days in which to match them. On Friday, May 26, DCDC informed Antioch's lawyer, Nathan Washer, that it could indeed meet the $825,000 figure.

On Tuesday of this week, however, NEMAC submitted another contract. Like the first, it was typed on plain white paper with no letterhead. It raised the ante to $9000,000 - $150,000 more than DCDC and the Kenesaw cooperative had been aiming for.

Wasser and Antioch officials said they do not know who the president or directors of NEMAC are, but the escrow deposit convinved them of the corporation's good faith.

Paul Goodrich, a Boston lawyer who signed the contracts on behalf of NEMAC said yesterday that he does not know who is behind the company, but was doing a favor for the Providence lawyer, Bruce M. Selya, who chartered the corporation last week.

Though Selya and two other members of his law firm, Selya and Iannucillo, are listed as principals on the articles of imcorporation filed last week, Selya said in a telephone interview Wednesday that he is merely representing the president and directors of NEMAC. Selya refused to say who those people are or whether any of them lives in Washington.

As Armstrong explained the situation, DCDC and the Kenesaw cooperative now have three alternatives: to try to meet the $900,000 offer by this evening; to see if Antioch can be persuaded to refuse the NEMAC contract, or "to go to the courts and let the courts work out some solutions."

Dudley Woodall, director of administration and finances for Antioch, who has been handling the deal for the university in Yellow Springs, Ohio, said he believed the building would go to NEMAC. "It's hard for me to think otherwise," he said.

Asked what NEMAC's plans for the building area, Woodall said he didn't know. "I suppose," he said, "they'll continue to develop it along the lines that that area of the city has been developing."

"Being a resident of Yellow Springs, Ohio, with 5,000 people," said Woodall, "I don't have such urban problems."