Method of preparing photochemotherapic alkylangelicin compounds

Process of producing alkylangelicins free from psoralens, of formula ##STR43## wherein R is alkyl, R.sub.1,R.sub.2,R.sub.3,R.sub.5 are independently hydrogen or alkyl, R.sub.6 is hydrogen, alkyl, hydroxymethyl, acetoxymethyl, metoxymethyl, as well as aminomethyl, alkylaminomethyl, dialkylaminomethyl or a group of formula ##STR44## wherein R.sub.7 and R.sub.8 are simultaneously hydrogen, methyl or ethyl, free or salified, characterized in that a 6-alkylumbelliferone O-derivative of formula ##STR45## wherein R,R.sub.1,R.sub.3 have the meaning above referred to, and R.sub.4 is an acyl residue of formula

• --CO--R.sub.9
• wherein R.sub.9 is an alkyl or
• an allyl residue of formula
• --CHR.sub.10 --CH=CHR.sub.11
• wherein R.sub.10 and R.sub.11 are independently hydrogen or alkyl, or a .beta.-ketoalkyl residue of formula
• --CHR.sub.12 --CO--CH.sub.2 R.sub.13
• wherein R.sub.12 and R.sub.13 are independently hydrogen or alkyl, is submitted to direct alkaline cyclization or to appropriate Fries or Claisen rearrangements and successive cyclization, thus yielding compound (1), wherein R.sub.5 and R.sub.6 are independently hydrogen or alkyl groups, and, when R.sub.6 of compound (1) is hydrogen, it is converted, through a treatment with chloromethylmethylether into the corresponding 4'-chloromethylangelicin, which is then converted into the corresponding 4'-hydroxymethyl, 4'-acetoxymethyl, 4'-aminomethyl, 4'-alkylaminomethyl, 4'-dialkylaminomethyl or 4'-aminoethoxymethyl or dimethylaminoethoxymethyl or 4'-diethylaminoethoxymethyl or 4'-diethylaminoethoxymethyl derivatives and finally, to obtain water-soluble compounds, the derivatives containing the amino group, substituted or not, are converted into the corresponding hydrochlorides.