A method for the solid phase synthesis of a protected, partially protected or unprotected insulin B-chain or an insulin B-chain derivative, the process comprising: preparing a lysine-resin conjugate comprising a resin and a lysine or a lysine derivative of the formula I, wherein: W is a resin of a formulae IIIa, IIIb, IIIc or IIId: wherein: n is 0, 1, 2 or 3; each R 1 and R 3 is independently selected from H or is independently selected from the group consisting of 2-Cl, 2-C 1-3 alkyl, 2-C 1-3 alkoxy, 4-C 1-3 alkyl, 4-C 1-3 alkoxy, provided that in each of the formulae IIIb, IIIc and IIId, only one of R 1 and R 3 is 2-Cl and only one of R 1 and R 3 is H; R 2 is the solid phase of the resin; and Z is a bond or -C(=O)-; R is selected from the group consisting of -OH, a carboxyl protecting group, -NH 2, -O-C 1-6 alkyl, -O-C 2-6 alkenyl, -O-tri-C 1-3 alkyl silyl, a peptide residue selected from the group consisting of -Pro-OH, -Pro-NH 2, -Pro-O-C 1-6 alkyl, -Pro-O-C 2-6 alkenyl, -Pro-O-tri-C 1-3 alkylsilyl, Thr, -Thr -Arg -Arg -OH, -Thr -Arg -Arg -NH 2, -Thr -Arg -Arg -O-C1-6 alkyl, -Thr -Arg -Arg -O-C 2-6 alkenyl,-Thr -Arg -Arg -O-tri-C 1-3 alkylsilyl, -Thr -OH, -Thr -NH 2, -Thr -O-C 1-6 alkyl, -Thr -O-C 2-6 alkenyl and -Thr -O-tri-C 1-3 alkylsilyl, a peptide residue comprising 1 to 200 amino acids comprising optionally protected side chain and optionally protected terminal carboxyl group; wherein Pr1 is hydrogen or a -OH protecting group and each Pr2 and PR3 is independently hydrogen or a guanidine protecting group; P is hydrogen, an amino protecting group, an N-terminus peptide residue comprising 1 to 200 amino acids comprising optionally protected side chain and optionally protected terminal amino group, wherein the N-terminus peptide residue comprises a C-terminus and an N-terminus; provided that when R is selected from the group consisting of -OH, a carboxyl protecting group, -NH 2, -O-C 1-6 alkyl, -O-C 2-6 alkenyl, -O-tri-C 1-3 alkyl silyl, a peptide residue selected from the group consisting of -Pro-OH, -Pro-NH 2, -Pro-O-C 1-6 alkyl, -Pro-O-C 2-6 alkenyl, -Pro-O-tri-C 1-3 alkylsilyl, Thr, -Thr -Arg -Arg -OH,-Thr -Arg -Arg -NH 2, -Thr -Arg -Arg -O-C1-6 alkyl, -Thr -Arg -Arg -O-C 2-6 alkenyl, -Thr -Arg -Arg -O-tri-C 1-3 alkylsilyl,-Thr -OH, -Thr -NH 2, -Thr -O-C 1-6 alkyl, Thr -O-C 2-6 alkenyl and-Thr -O-tri-C 1-3 alkylsilyl, then P is not hydrogen or an amino protecting group; coupling the lysine-resin conjugate of the formula I, wherein R is selected from - OH, a carboxyl protecting group and a peptide residue comprising 1 to 200 amino acids comprising optionally protected side chain and optionally protected terminal carboxyl group, with a protected, partially protected or unprotected peptide residue Ib, where the peptide residue comprising 1 to 200 amino acids and the peptide residue Ib together comprises the insulin B-chain or the insulin B-chain derivative, to form the protected, partially protected or unprotected insulin B-chain or an insulin B-chain derivative. n is 0, 1, 2 or 3; each R 1 and R 3 is independently selected from H or is independently selected from the group consisting of 2-Cl, 2-C 1-3 alkyl, 2-C 1-3 alkoxy, 4-C 1-3 alkyl, 4-C 1-3 alkoxy, provided that in each of the formulae IIIb, IIIc and IIId, only one of R 1 and R 3 is 2-Cl and only one of R 1 and R 3 is H; R 2 is the solid phase of the resin; and Z is a bond or -C(=O)-; R is selected from the group consisting of -OH, a carboxyl protecting group, -NH 2, -O-C 1-6 alkyl, -O-C 2-6 alkenyl, -O-tri-C 1-3 alkyl silyl, a peptide residue selected from the group consisting of -Pro-OH, -Pro-NH 2, -Pro-O-C 1-6 alkyl, -Pro-O-C 2-6 alkenyl, -Pro-O-tri-C 1-3 alkylsilyl, Thr, -Thr -Arg -Arg -OH, -Thr -Arg -Arg -NH 2, -Thr -Arg -Arg -O-C1-6 alkyl, -Thr -Arg -Arg -O-C 2-6 alkenyl,-Thr -Arg -Arg -O-tri-C 1-3 alkylsilyl, -Thr -OH, -Thr -NH 2, -Thr -O-C 1-6 alkyl, -Thr -O-C 2-6 alkenyl and -Thr -O-tri-C 1-3 alkylsilyl, a peptide residue comprising 1 to 200 amino acids comprising optionally protected side chain and optionally protected terminal carboxyl group; wherein Pr1 is hydrogen or a -OH protecting group and each Pr2 and PR3 is independently hydrogen or a guanidine protecting group; P is hydrogen, an amino protecting group, an N-terminus peptide residue comprising 1 to 200 amino acids comprising optionally protected side chain and optionally protected terminal amino group, wherein the N-terminus peptide residue comprises a C-terminus and an N-terminus; provided that when R is selected from the group consisting of -OH, a carboxyl protecting group, -NH 2, -O-C 1-6 alkyl, -O-C 2-6 alkenyl, -O-tri-C 1-3 alkyl silyl, a peptide residue selected from the group consisting of -Pro-OH, -Pro-NH 2, -Pro-O-C 1-6 alkyl, -Pro-O-C 2-6 alkenyl, -Pro-O-tri-C 1-3 alkylsilyl, Thr, -Thr -Arg -Arg -OH,-Thr -Arg -Arg -NH 2, -Thr -Arg -Arg -O-C1-6 alkyl, -Thr -Arg -Arg -O-C 2-6 alkenyl, -Thr -Arg -Arg -O-tri-C 1-3 alkylsilyl,-Thr -OH, -Thr -NH 2, -Thr -O-C 1-6 alkyl, Thr -O-C 2-6 alkenyl and-Thr -O-tri-C 1-3 alkylsilyl, then P is not hydrogen or an amino protecting group; coupling the lysine-resin conjugate of the formula I, wherein R is selected from - OH, a carboxyl protecting group and a peptide residue comprising 1 to 200 amino acids comprising optionally protected side chain and optionally protected terminal carboxyl group, with a protected, partially protected or unprotected peptide residue Ib, where the peptide residue comprising 1 to 200 amino acids and the peptide residue Ib together comprises the insulin B-chain or the insulin B-chain derivative, to form the protected, partially protected or unprotected insulin B-chain or an insulin B-chain derivative.