Production of bitter principle derivatives

A compound of general formula 1

• wherein:
• (i) X− represents halogenide, sulphate, benzoate, acetate, trifluoroacetate, hydroxide, saccharinate, or capsaicinate,
• (ii) R1-R10 independently represent:
• (a) hydrogen,
• (b) halogen,
• (c) C1-C5 alkyl,
• (d) C1-C4 alkoxy,
• (e) C1-C20 alkoxycarbonyl
• (f) —NH—P or —O—P, wherein P is a hydrogen
• or a residue consisting of 1-30 amino acids selected from the group consisting of D-amino acids, L-amino acids and unnatural amino acids, wherein said amino acids are optionally modified for coupling,
• (g) —(Y)n—COOM with M=Na, K, or [N(R12)4]+, or
• (h) —(Y)n—C(O)NR14R15, further wherein Y represents an organic residue selected from the group consisting of:
• —CH2, —CH(CH3)—, —CH2—CH2—, —(CH2)3—, —CH═CH—, —C≡C—, —O—CH2—CH2—, —O—CH2—CH2—O—CH2—CH2—, and —NH—CH2—CH2— and n=0 or 1,
• (iii) R14 and R15 represent hydrogen, a C1-C12 alkyl, or a residue consisting of 1-30 amino acids selected from the group consisting of D-amino acids, L-amino acids and unnatural amino acids, and
• (iv) at least one of the residues R1-R10 is a (a) —(Y)n—COOM or (b) —(Y)n—C(O)NR14R15, wherein Y, M, R14, and R15 are as defined above, and
• (v) R11 and R12 independently represent hydrogen or a C1-C10 alkyl residue.