PITTSBURGH — A Pittsburgh-area businessman convicted of defrauding a chemical company and evading federal income taxes was sentenced to 18 months in a federal prison.

Timothy A. Heffner, 45, of Pine Township, Allegheny County, pleaded guilty in July to conspiracy to commit mail fraud and wire fraud as well as two counts of tax evasion for failure to pay more than $1.2 million in taxes.

A judge also fined Heffner $7,500 and ordered him to pay $139,000 in restitution to St. Louis-based Sigma Aldrich Corp., a chemical supplier to research labs.