CHROMAN-4-ONES

Prepn. of chroman-4-ones of formula (I) comprises reacting an o-hydroxycarbonyl cpd. (II) with a carbonyl cpd. (III) in the presence of an amine HNR9R10 R1-R4 are independently H, alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, alkoxycarbonyl, carboxy or aminoalkyl, all opt. substd.; R2-R4 may also be NH2 or dialkylamino and R1+R2 may together form a carbocyclic or heterocyclic ring. R5-R8 are independently H, halo, OH, NO2, CN, COOH, alkyl, cycloalkyl, aryl, aralkyl, alkoxy, aralkoxy, aryloxy, alkoxycarbonyl, amino (opt. with 1 or 2 alkyl substits.) or acylamino, all opt. substd. R9 and R10 are alkyl or together complete a heterocycle. (I) are new when (i) R1 and CHR2R3 are together (CH2)m (m = 4-12); (ii) R1 = (CH2)n.R19 (n = 1-18; R19 = H, amino (mono- or di-alkyl substd.), COOH or alkoxycarbonyl); (iii) R1 = H or 1-18C alkyl; R2 = opt. substd. aryl, aralkyl or alkoxycarbonyl, dialkylamino, -R24.NR25R26 or COOR27 (R24 = alkylene; R25, R26 and R27 = H or alkyl) and R3 = H or alkyl; and (iv) where CHR2R3 = 1-18C alkenyl or the residue of a 1-6C alkanoic acid; R1 = H or 1-6C alkyl; R5 = H or CH3; R6 = OH, halo or CH3; R7 and R8 are same or different H or CH3. (I) have pharmaceutical activity (no details), are herbicides and antioxidants and the specific cpd. 2,5,8-tetramethyl-6-hydroxy-2-(4',8',12')-trimethyltridecatrien-(- 3',7',11')-ylchroman-4-one is an intermediate for Vitamin E. The process is simple, gives high yields, allows easy recovery of amine for recycle and is completely non-polluting.