A 50-year-old Washington man, who directed a sophisticated scheme to defraud failing American businesses with worthless checks drawn mainly on a now-defunct Caribbean bank, was sentenced in U.S. District Court yesterday to serve two to seven years in prison.

H. Neil Kelly, of 4809 Bending La. NW, was described by the government prosecutor as a "one-man crime wave." Assistant U.S. attorney Brian W. Shaughnessy said in court papers that Kelly gained the confidence of struggling businessmen with "glittering words" and then "fleeced them mercilessly" by way of the complicated fraud scheme.

Kelly collected about $97,000 as a result of the scheme, the government said.

Kelly's attorney, Kenneth Robinson, yesterday described his client as a "likeable guy" who was "not interested . . . in ripping off people for money" but thought instead that he had concocted a profit-making scheme for them.

After a two-month trial, a federal jury convicted Kelly last May of nine counts of mail fraud and one count of interstate transportation of securities taken by fraud.

Yesterday, Judge George L. Hart Jr. sentenced Kelly to serve two to seven years on the securities charge and concurrent terms of 2 months to five years on each of the mail fraud counts.

Hart ordered, however, that the sentences here run consecutively with a one-to-four-year prison term Kelly received for a 1976 Florida conviction for interstate shipment of stolen property. Kelly has asked the U.S. Supreme Court to review that conviction, Robinson said.

Kelly also faces fraud charges in Alaska.

Kelly was convicted twice in Washington in the 1960s on felony charges involving false pretenses.

The scheme for which Kelly was sentenced yesterday took place between September 1974 and November 1975.

According to government evidence, Kelly approached businessmen here and offered to give them financial assistance through checks drawn on the Antilles Bank and Trust Company in Antigua and on banks in the United States.

The monies were then used by the businesses to pay off some of their creditors before it was discovered that the checks drawn were worthless, the government said. In the meantime, Kelly in exchange, received money from the businesses, which he claimed he needed to finance his own ventures.

The government also contended that Kelly and others used phony invoices for copy paper purchased from a New York manufacturer to secure a large bank loan. According to the government, the Chase Manhattan Bank lost over $500,000 in loans in connection with the scheme.

Also convicted with Kelly was Thomas Cuni, of Fort Mitchell, Ky., whom the government said was Kelly's business partner and front man. Judge Hart earlier fined Cuni $19,000 after the jury found him guilty of nine counts of mail fraud and one count of perjury.

The jury deadlocked on mail fraud, securites and false pretense charges against a third man, Daniel Price, who owned the Occidental Restaurant at 1411 Pennsylvania Ave. NW.