4H-1-benzopyrans and lubricant compositions containing same

A process which comprises reacting one molar proportion of an aminomethylphenol corresponding to the formula:

• ##STR6## with about 1-10 molar proportions of a 1,3-diketone corresponding to the formula R.sub.3 COCH.sub.2 COR.sub.4 and about 1-10 molar proportions of an alkali or alkaline earth metal hydroxide at a temperature of at least about 50.degree. C. and a pressure in the range of from atmospheric up to about 1000 psig so as to form a 4H-1-benzopyran corresponding to the formula:
• ##STR7## in which formulas R.sub.1 and R.sub.2 are independently selected from the group consisting of hydrogen and alkyl radicals containing about 1-10 carbons, and R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are alkyl radicals containing about 1-10 carbons.

A lubricating oil composition normally susceptible to oxidative deterioration containing an antioxidant amount of a compound corresponding to the formula:

• ##STR8## wherein R.sub.1 and R.sub.2 are independently selected from the group consisting of hydrogen and alkyl radicals containing about 1-10 carbons, and R.sub.3 and R.sub.4 are independently selected from alkyl radicals containing about 1-10 carbons.

A compound corresponding to the formula:

• ##STR9## wherein R.sub.1 and R.sub.2 are independently selected from the group consisting of hydrogen and alkyl radicals containing about 1-10 carbons, and R.sub.3 and R.sub.4 are independently selected from alkyl radicals containing about 1-10 carbons.