When Robert Gladstone and James Crozier attended Brooklyn Technical High School in the late 1940s, they did not know one another. The native New Yorkers met later at the University of North Carolina when they were doing graduate work.

But they never expected to be in business together years later in Washington and then to be the top executives of the firm (Quadrangle Development Corp.) that was selected last week, along with Marriott Corp. and Rouse Co., to develop the new hotel-office-commercial complex that will be wrapped around the National Theater in a total $110 million project.

Although known and respected within the world of commercial real estate. Gladstone and Crozier are far less known to the public than anyone named Marriott or Rouse. One of the reasons might be their attitude toward their victory in the Pennsylvania Avenue redevelopment competition. Asked how they were going to celebrate, Gladstone said: "By working. Now the real work begins."

But a small banner proclaimed the victory in the Gladstone office at 2030 M St. NW, a building that was the first to be developed here by Quadrangle in 1972.Gladstone has been an economic and real estate consultant since college. He founded Gladstone Associates in 1963 and got into local development with Crozier in 1970. The graduate school friends became a business team. In explaining the more into the role of entrepreneur. Gladstone said simply: "We decided to put our money where our mouths were."

Neither Quadrangle's president (Gladstone) nor executive vice president (Crozier) are even slightly flamboyant, egotistical or given to the hard sell. Rather they are intense and knowledgeable devotees of the work ethic. But they can smile without forcing it.

Gladstone, whose career as an economic constultant spans more than 20 years, is 5 foot 6 and trimmer than a few years ago at 160 pounds. He wears gold-rimmed glasses and has curly, slightly graying dark hair. He and his wife live in a single house in North-west. They have three children. Gladstone reluctantly admitting to doing something on the ski slopes and thennis and squash courts when there is time.

Crozier, who has a degree in architechure and a master's in city planning, has worked in low-income housing development, central city redevelopment and also had a stint as director of development for Columbus, Ohio. He's 5 foot 10, 180 pounds, slightly florid in complexion and has sandy, straight hair. He and his wife and two children live in Reston. He plays tennis and racquetball.

Quadrangle's development interests are in Washington's downtown. They have had six major projects here. The newest, the 1301 Pennsylvania office building started this summer, will dominate the southeast corner of the block. They are completing a large office building between 19th and 26th streets on Prennsylvania Avenue. It will have an internal Pepco substation and more than 200,000 square feet of office space that is 90 percent leased prior to scheduled completion in February.

In dress, dialogue and demeanor, neither Gladstone nor Crozier exudes any of the usual trappings of success that they have enjoyed. They have taken their big "Avenue" victory with restraint but not without being humanly able to savor the flavor. On the role of the developer. Gladstone said (while Crozier nodded agreement):

"Development is not just bricks and mortar. it means recognition of the public interest in environment, preservation and a focal point for public policy."

Crozier does his share of the talking. Asked about Quadrangle's one experience with building a high-rise downtown rental apartment at 22d and P Sts. NW a few years ago, he said: "It was not a big commercial success because of rent control. And rent control is the reason why we have not seen fit to do any more apartments in the city."

If this pair has a professional ego, it might be seen in the Gladstone statement: "We will not put up a building that we would not be willing to have our pictures taken in front of."

Quadrangle decided last May to get into the competition for "Parcel 254-A, Square 254" site on the Avenue. The Marriott Corp, was enlisted as a partner because of a respect for that firm's hotel record and because the hotel aspect of the project was regarded as highly important. Gladstone said the prices of rooms in the hotel will be less, even when completed in 1983, than the top level (more than $80) for conventional rooms in some downtown hotels today.

Asked about a name for the project. Gladstone and Crozier said that's still on the agenda. Crozier joked: "Maybe we'll call the hotel the Willard" (for J. Willard Marriott), laughing because he knows another developer will be chosen soon to do the nearby old Willard Hotel that has been dark for so many years.

"That's the real beauty of the hotel part of this complex," added Crozier seriously."It will put people in downtown and so will the preserved National Theatre and the type of festival retail shops that the Rouse Co. will devise for the commercial space."

SHORTLY: Architects for the project will be the associated firms of Frank Schlesinger FAIA, of Washington, and Mitchell-Giurgola. Philadelphia . . . Crozier and Gladstone said that they had been congratulated by John (Skip) Akridge, a former employe, whose proposal was not chosen. But none from the National Press club people . . . If the Press Club building should become a part of the total project, it will be a second phase . . . No builder has been chosen for the first phase but it will be let as one contract. Work is expected to begin late in 1979 or early in 1980.